Enclosures housing cell-coated supports for treating tumors

ABSTRACT

The present invention relates to devices, systems and methods for treating tumors. In particular, the present invention relates to enclosures housing cell-coated supports for promoting regression of tumors, such as cancerous tumors, papillomas, and warts. In preferred embodiments, the present invention provides methods of promoting tumor regression employing enclosures secreting therapeutic proteins.

The present application is a Continuation-in-part of U.S. applicationSer. No. 09/640,990, filed Aug. 18, 2000, which claims priority to U.S.provisional application 60/149,744, filed Aug. 19, 1999, the contents ofwhich are both hereby incorporated by reference.

The present application was funded in part with government support underNIH grant numbers FM 44918 and GM 50401. The government has certainrights in this invention.

FIELD OF THE INVENTION

The present invention relates to devices, systems, kits and methods fortreating tumors. In particular, the present invention relates toenclosures housing cell-coated supports for promoting regression oftumors, such as cancerous tumors, neoplasms, papillomas, and warts.

BACKGROUND OF THE INVENTION

Each year, about one million people in the United States are diagnosedwith skin cancer. Skin cancer is the most common type of cancer in theUnited States. According to recent estimates, 40 to 50 percent ofAmericans who live to age 65 will have skin cancer at least once.

The two most common kinds of skin cancer are basal cell carcinoma andsquamous cell carcinoma. Basal cell carcinoma accounts for more than 90percent of all skin cancers in the United States. Basal cell carcinomais a slow-growing cancer that seldom spreads to other parts of the body.Squamous cell carcinoma also rarely spreads, but it does so more oftenthan basal cell carcinoma. However, it is important that skin cancers befound and treated early because they can invade and destroy nearbytissue. Basal cell carcinoma and squamous cell carcinoma are known asnonmelanoma skin cancer.

Another type of cancer that occurs in the skin is melanoma, which beginsin the melanocytes. The American Cancer Society reports that melanomaaccounts for only 4 percent of skin cancer cases, but causes about 79%of skin cancer deaths. The American Cancer Society predicts that 16percent of the newly diagnosed cases in the year 2000 will result indeath.

Medical evidence indicates that the cytokine IL-I inhibits tumor growth.However, systemic administration is very toxic to the human body.Therefore, what is needed are methods and devices for delivering tumorinhibiting compounds without systemic toxicity.

SUMMARY OF THE INVENTION

The present invention provides devices, kits, systems and methods fortreating tumors. In particular, the present invention providesenclosures housing cell-coated supports (e.g., populated with cells) forpromoting regression of tumors, such as cancerous tumors, papillomas,and warts.

In certain embodiments, the present invention provides methods forpromoting tumor regression, comprising; a) providing; i) viable cells ona solid support, wherein the viable cells secrete at least onetherapeutic protein, ii) an enclosure housing the solid support, whereinthe enclosure comprises a material comprising pores, and iii) a subjectwith a tumor, and b) positioning the enclosure on the tumor of thesubject such that regression of the tumor is promoted. In someembodiments, the present invention provides methods for promoting tumorregression, comprising; a) providing; i) viable cells on a solidsupport, wherein the viable cells secrete at least one therapeuticprotein, ii) an enclosure housing the solid support, wherein theenclosure comprises mesh material, and iii) a subject with a tumor, andb) positioning the enclosure on the tumor of the subject such thatregression of the tumor is promoted. In certain embodiments, the methodfurther comprises performing a tumor susceptibility assay (e.g. beforepositioning the enclosure on the tumor). In particular embodiments,method further comprises performing a cell viability assay. In certainembodiments, the enclosure functions as the solid support (e.g. thecells are on the inside of the enclosure, instead of being on a separatesolid support).

In some embodiments, the present invention provides methods forpromoting tumor regression, comprising; a) providing; i) viable cells ona first solid support, wherein the viable cells secrete (or may beinduced to secrete) at least one therapeutic protein, ii) a second solidsupport (e.g. sticky dressing), and iii) a subject with at least onetumor, and b) adhering the first solid support to the second solidsupport, and c) positioning the second solid support on the tumor of thesubject such that regression of the tumor is promoted.

In certain embodiments, the present invention provides methods forpromoting tumor regression, comprising; a) providing; i) viable cells ona solid support, wherein the viable cells secrete (or may be induced tosecrete) at least one therapeutic protein, ii) an enclosure housing thesolid support, wherein the enclosure comprises mesh material, and iii) asubject with at least one skin cancer tumor (e.g. melanoma, sarcoma, orcarcinoma), and b) positioning the enclosure on the skin cancer tumor ofthe subject such that regression of the tumor is promoted. In particularembodiments, the skin cancer tumor is a head melanoma or neck melanoma.In some embodiments, the positioning comprises topical application ofthe enclosure to the skin cancer related tumor. In other embodiments,the positioning step causes the therapeutic protein to contact thetumor. In certain embodiments, the method further comprises performing atumor susceptibility assay (e.g. before positioning the enclosure on thetumor). In particular embodiments, method further comprises performing acell viability assay.

In certain embodiments, the present invention provides methods forproducing a cell-containing enclosure for promoting tumor regression,comprising; a) providing, i) viable cells on solid support material, ii)a nucleic acid sequence encoding at least one therapeutic protein,wherein the therapeutic protein promotes tumor regression, and iii) anenclosure configured for housing the solid support material, wherein theenclosure comprises mesh material; and b) transfecting the viable cellson the solid support material with the nucleic acid sequence underconditions such that transfected cells are generated that secrete saidtherapeutic protein, and c) placing the solid support material into theenclosure to produce a cell-containing enclosure configured forpromoting tumor regression (e.g. when placed on a tumor, such as a skincancer tumor). In some embodiments, the transfection step employsliposomes. In preferred embodiments, the present invention providescell-containing enclosures configured for promoting tumor regressionthat are produced by the methods of the present invention. In certainembodiments, the cells are tranfected prior to being seeded on the solidsupport material. In other embodiments, the therapeutic protein promoteswound healing, and the enclosure produced is configured for promotingwound healing.

In other embodiments, the present invention provides methods forproducing a cell-containing enclosure for promoting tumor regression,comprising; a) providing, i) solid support material, ii) a culturemedium comprising viable cells, iii) a vector comprising a nucleic acidsequence encoding a therapeutic protein, wherein the therapeutic proteinpromotes tumor regression, and iv) an enclosure configured for housingthe solid support material, wherein the enclosure comprises meshmaterial, b) immersing the solid support in the culture medium underconditions such that viable cells migrate onto the solid supportmaterial, c) transfecting the viable cells with the vector, and d)introducing the solid support material into the enclosure to produce acell-containing enclosure configured for promoting tumor regression(e.g. when placed on a tumor). In preferred embodiments, the presentinvention provides cell-containing enclosures configured for promotingtumor regression that are produced by the methods of the presentinvention. In other embodiments, the therapeutic protein promotes woundhealing, and the enclosure produced is configured for promoting woundhealing.

In particular embodiments, the present invention provides methods forproducing a cell-containing enclosure for promoting tumor regression,comprising; a) providing, i) viable cells comprising a nucleic acidsequence encoding a therapeutic protein, wherein the therapeutic proteinpromotes tumor regression, and ii) an enclosure housing solid supportmaterial, wherein the enclosure comprises mesh material, and b)introducing the viable cells into the enclosure under conditions suchthat the viable cells attach to the solid support material. In preferredembodiments, the present invention provides cell-containing enclosuresconfigured for promoting tumor regression that are produced by themethods of the present invention.

In some embodiments, the present invention provides methods forproducing a cell containing enclosure for promoting tumor regression,comprising; a) providing, i) solid support material, ii) viable cellscomprising a nucleic acid sequence encoding a therapeutic protein,wherein the therapeutic protein promotes tumor regression, and iii) anenclosure configured for housing the solid support material, wherein theenclosure comprises mesh material, and b) placing the solid supportmaterial into the enclosure, and sealing the enclosure, and c)introducing the viable cells into the enclosure under conditions suchthat the viable cells attach to the solid support material. In certainembodiments, the viable cells are injected into the enclosure. In otherembodiments, the methods further comprise the step of freezing theenclosure containing the viable cells. In further embodiments, themethods further comprise the step of thawing the enclosure containingthe viable cells. In other embodiments, the methods further comprise thestep of thawing the enclosure containing the viable cells andmaintaining the thawed enclosure in a tissue culture medium. Inparticular embodiments, the methods further comprise the step ofperforming a cell viability assay.

In certain embodiments of the present invention, the solid supportmaterial is treated with an composition giving the solid supportmaterial a negative charge (e.g. a net negative charge, or making thesolid support material more negatively charged than the enclosure and/ortumor). In preferred embodiments, the solid support material is treatedwith a hydroxide solution (or similar solution) prior to placement(introduction) into the enclosure.

In some embodiments, the present invention provides enclosuresconfigured for promoting tumor regression comprising mesh materialhaving pores, wherein the enclosure houses viable cells on a solidsupport, wherein the viable cells comprise an expression vector, andwherein the expression vector comprises a nucleic acid sequence encodinga therapeutic protein useful for promoting tumor regression (e.g. IL-1,tumor necrosis factor alpha, etc). In certain embodiments, the vectorencodes at least two therapeutic proteins (e.g. one cytokine and onetumor suppressor, or two cytokines, etc.).

In particular embodiments, the present invention provides systems andkits for promoting tumor regression, comprising; a) an enclosureconfigured for housing solid support material, b) solid supportmaterial, and c) a nucleic acid sequence encoding a therapeutic protein,wherein the therapeutic protein promotes tumor regression. In furtherembodiments, the system and kits of the present invention furthercomprise an insert component comprising writing instructions: (e.g. howto assemble the components to produce a cell-containing enclosurecapable of promoting tumor regression, and/or how to employ the systemor kit to treat tumors). In other embodiments, the present inventionprovides systems and kits for promoting tumor regression, comprising; a)an enclosure configured for promoting tumor regression comprising meshmaterial having pores, wherein the enclosure houses viable cells on asolid support, wherein the viable cells comprise an expression vector,the expression vector comprises a nucleic acid sequence encoding atherapeutic protein, and b) an insert component comprising writteninstructions on how to use the enclosure to promote tumor regression ina subject. In certain embodiments, the various kit and system componentsare in separate containers or packages (e.g. separate vials). In someembodiments, the kits and systems of the present invention comprise adressing (e.g. TEGADERM) that may be placed over the enclosure.

In certain embodiments, the therapeutic protein is a recombinant protein(e.g. the viable cells are transfected with a vector encoding theprotein). In other embodiments, the therapeutic protein is naturallyexpressed by the viable cells (e.g. a cell line found or made toover-express a protein useful in promoting tumor regression).

In particular embodiments, the therapeutic protein is a cytokine,antibody, hormone, or steroid. In some embodiments, the therapeuticprotein is a human or humanized antibody (e.g. Trastuzumab (HERCEPTIN)Genentech BioOncology/Roche, or Daclizumab (ZENAPAX), Protein DesignLabs/Roche). In some embodiments, the therapeutic protein is a cytokine.In certain embodiments, the therapeutic protein is selected frominterleukin-1, interleukin-2, interleukin-4, interleukin-6,interleukin-7, interleukin-10, interleukin-12, interferon-alpha,interferon-beta, interferon-delta, tumor necrosis factor-alpha, tumornecrosis factor-beta, granulocyte-macrophage colony stimulating factor(GM-CSF) and granulocyte colony stimulating factor (G-CSF). Inparticular embodiments, the therapeutic protein is a tumor suppressorprotein. In certain embodiments, the tumor suppressor protein isselected from APC, BRCA1, BRCA2, CDH1, CKKN1C, CDKN2A, CYLD, EP300,EXT1, EXT2, MADH4, MAP2K4, MEN1, MLH1, MSH2, NF1, NF2, PRKAR1A, PTCH,PTEN, RB1, SDHD, SMARCB1, STK11, TP53, TSC1, TSC2, VHL, WT1, orcombinations thereof. In preferred embodiments, the therapeutic proteincomprises interleukin-1.

In certain embodiments, the viable cells comprise a nucleic acidsequence encoding the therapeutic protein. In particular embodiments,the nucleic acid sequence is exogenous. In some embodiments, the nucleicacid sequence encodes is a cytokine, antibody, hormone, or steroid. Insome embodiments, the nucleic acid sequence encodes a humanized antibody(e.g. Trastuzumab, or Daclizumab). In certain embodiments, the nucleicacid sequence encodes a cytokine. In other embodiments, the nucleic acidsequence encodes a protein selected from interleukin-1, interleukin-2,interleukin-4, interleukin-6, interleukin-7, interleukin-10,interleukin-12, interferon-alpha, interferon-beta, interferon-delta,tumor necrosis factor-alpha, tumor necrosis factor-beta,granulocyte-macrophage colony stimulating factor (GM-CSF) andgranulocyte colony stimulating factor (G-CSF). In particularembodiments, the nucleic acid sequence is a tumor suppressor gene. Incertain embodiments, the tumor suppressor gene is selected from APC,BRCA1, BRCA2, CDH1, CKKN1C, CDKN2A, CYLD, EP300, EXT1, EXT2, MADH4,MAP2K4, MEN1, MLH1, MSH2, NF1, NF2, PRKAR1A, PTCH, PTEN, RB1, SDHD,SMARCB1, STK11, TP53, TSC1, TSC2, VHL, WT1, or combinations thereof. Insome embodiments, the nucleic acid sequence is derived from the subjectwith the tumor (e.g., an IgG encoding nucleic acid sequence from thesubject to be treated). In preferred embodiments, the nucleic acidsequence comprises a least a portion of the human interleukin-1 gene. Incertain embodiments, the solid support material comprises beads. Inpreferred embodiments, the solid support comprises macroporous beads. Inother embodiments, the beads comprise polyethylene. In certainembodiments, the beads further comprise silica. In other embodiments,the solid support material comprises a collagen coating. In particularlypreferred embodiments, the solid support material comprises CYTOLINE 1beads, or similar beads. In certain embodiments, the enclosure functionsas the solid support material.

In certain embodiments, the viable cells are selected from fibroblasts,keratinocytes, endothelial cells, melanocytes, smooth muscles cells,fetal fibroblasts, macrophages, epithelial cells, stem cells (e.g.,adult stem cells, embryonic stem cells), and combinations thereof. Insome embodiments, the viable cells are derived from the subject. Inother embodiments, the cells are mouse cells, human cells (e.g. humanforeskin cells or derived from human foreskin cells).

In some embodiments, the mesh material comprises pores. In particularembodiments, the pores are large enough to permit viable cells on thesolid support to cross the mesh material. In other embodiments,positioning the enclosure on the tumor allows less than 5%, 3%, or 1% ofthe viable cells to cross the mesh material. In certain embodiments,there are no detectable cells (e.g. by visual inspection) that pass fromthe enclosure onto the tumor. In some embodiments, the solid supportmaterial has a net negative charge. In other embodiments, the solidsupport material is more negatively charged than the mesh material Inpreferred embodiments, the cells have a higher avidity for the solidsupport material than for the mesh material or the tumor.

In particular embodiments, the mesh material has pores ranging in sizefrom about 1 micron to about 500 microns. In other embodiments, the meshmaterial has pores ranging in size from about 10 microns to about 400microns. In preferred embodiments, the mesh material has pores rangingin size from about 10 microns to about 300 microns. In certainembodiments, the mesh material has pores with a size of approximately300 microns (e.g. 295-305 microns). In certain embodiments, the poresare too small to permit the viable cells on the solid support to crossthe mesh material. In some embodiments, the mesh material comprisespolyethylene (e.g. a DELNET bag/material). In other embodiments, themesh material is selected from polyester, nylon, or polyethylene.

In some embodiments of the methods of the present invention, the methodfurther comprises a step of removing the enclosure from the tumor afterregression of the tumor is promoted (e.g., after the size of the tumorhas decreased, or there are no longer visible signs of a tumor). Inparticular embodiments, the enclosures of the present invention furthercomprise a removal component (e.g. string, handle, tab, or the like). Insome embodiments, the methods of the present invention further comprisecovering the enclosure (on the tumor) with a dressing. In particularembodiments, the enclosures of the present invention are sealable. Inother embodiments, the enclosures are sealed.

In certain embodiments, the subject (e.g., with a tumor) is a mammal(e.g., human, cat, dog, cow, pig, etc.). In preferred embodiments, thesubject is a human. In particularly preferred embodiments, the subjectis a human with skin cancer. In some embodiments, the tumor (i.e. thetumor contacted with the cell-containing enclosure) is a canceroustumor. In preferred embodiments, the cancerous tumor is skin cancertumor (e.g. head and/or neck melanoma). In other embodiments, the tumoris a papilloma. In further embodiments, the tumor is wart.

A wide variety of tumors (e.g., cancer, papillomas and warts) can betreated by the methods, compositions, kits and systems of the presentinvention. Representative examples include, but are not limited to,colon carcinoma, prostate cancer, breast cancer, lung cancer, skincancer, liver cancer, bone cancer, ovary cancer, pancreas cancer, braincancer, head and neck cancer, lymphoma and other tumors. Representativeexamples of papillomas include, but are not limited to, squamous cellpapilloma, choroid plexus pappilloma and laryngeal papilloma.Representative examples of wart conditions include, but are not limitedto, genital warts, plantar warts, epidermodysplasia verruciformis andmalignant warts.

In certain embodiments, the present invention provides methods ofgenerating enclosures with customer-specific characteristics. Forexample, the viable cells of the present invention may be transfectedwith a particular nucleic acid sequence specified by a user. As user,for example, may send an enclosure manufacturer information regardingthe nucleic acid sequence to be used to transfect the cells (e.g. maycommunicate the name of a gene, or may send a sequence to be made), or auser may physically send the nucleic acid sequence to be used (e.g. as asource of the nucleic acid sequence to be used). In certain embodiments,information regarding the nucleic acid sequence to be used to transfectthe viable cells is sent over the Internet (e.g. the sequence to be usedis sent over the Internet or World Wide Web). In preferred embodiments,this information directs automated methods to produce enclosurescontaining solid supports with cells containing the user desired nucleicacid sequence. These enclosures, in some embodiments, are then shippedto the user (e.g. the enclosures are frozen or otherwise prepared forshipping and sent to a user, such as a doctor treating a patient with atumor).

In other embodiments, the present invention is directed to systems andmethods for enhancing the healing of wounds, including post surgicalwounds and chronic wounds (e.g., diabetic wounds, pressure sores),involving the use of cultured cells. In some embodiments, the inventioncontemplates the use of cultured keratinocytes grown on a transplantablesolid support. In other embodiments, the invention contemplates the useof transformed cells capable of secreting proteins beneficial in woundhealing (e.g. cytokines and growth factors grown on a transplantablesolid support).

The present invention is not limited by the nature of the transplantablesolid support (solid support material); indeed, the present inventioncontemplates the use of any three-dimensional support or matrix to whichcells will adhere, divide, and maintain their functional behaviors(e.g., heal wounds, or promote tumor regression). In some embodiments,the solid support comprises beads, and in further embodiments, the beadsare macroporous. In the preferred embodiments, the solid supportcomprises polyethylene silica-coated beads. In particular embodiments,the beads are placed in an enclosure, compartment, bag, or similarbarrier, the enclosure having pores, and the enclosure is then placed atthe wound site for use as an interactive wound healing promoter.

The present invention is not limited by the nature of the enclosure;however, in one embodiment, the pores are large enough to permit thecells from the beads to exit the enclosure into the wound, while inanother embodiment, the pores are too small to permit cells from thebeads to exit the enclosure, but large enough to permit cellular factorsto exit the enclosure or wound fluid components to enter the enclosure.In certain embodiments, the enclosures are replaced every few days untilthe wound heals (e.g., once a week).

In additional embodiments, the enclosure comprises a mesh material,having pores. In certain embodiments, the mesh material comprisespolyethylene. In one embodiment, the pores are large enough to permitthe cells from the beads to exit the enclosure into the wound, while inanother embodiment, the pores are too small to permit cells from thebeads to exit the enclosure, but large enough to permit cellular factors(e.g., cytokines) to exit the enclosure or wound fluid components toenter the enclosure.

Moreover, in further embodiments, the enclosure comprises abiocompatible membrane. In additional embodiments, the enclosurecomprises means for removing the enclosure from a wound. In particularembodiments, the removal means comprises a handle or string attached tothe enclosure.

In another embodiment, the present invention provides a system for thetreatment of wounds, comprising a) keratinocytes on a solid support; andb) an enclosure, the enclosure housing the solid support. While thepresent invention is not limited to the nature of the keratinocytes, ina preferred embodiment the keratinocytes are viable and growing.

In another embodiment, the present invention provides systems andmethods for enhancing the healing of wounds involving the use oftransformed cells. The transformed cells may be any secretory cell,transformed with a gene encoding a protein beneficial in wound healing(e.g. a cytokine or growth factor). More specifically, a system for thetreatment of wounds is provided comprising a) transformed cells on asolid support; and b) an enclosure, the enclosure housing the solidsupport.

The present invention also contemplates a method for treating a wound,comprising a) providing: i) keratinocytes on a solid support, ii) anenclosure, and iii) a subject having a least one wound; b) placing thekeratinocyte-containing solid support into the enclosure so as toproduce a keratinocyte-containing enclosure; and c) positioning thekeratinocyte-containing enclosure in the wound of the subject underconditions such that the healing of the wound is promoted. Additionalembodiments further comprise, after step b) and prior to step c),sealing the enclosure to produce a sealed keratinocyte containingenclosure. Finally, some embodiments further comprise step d), coveringthe wound containing the keratinocyte-containing enclosure with adressing.

The present invention further provides a method for treating a woundcomprising a) providing: i) transformed cells on a solid support, ii) anenclosure, and iii) a subject having at least one wound; b) placing thetransformed cell-containing solid support into the enclosure so as toproduce a transformed cell-containing enclosure; and c) positioning thetransformed cell-containing enclosure in the wound of the subject underconditions such that the healing of the wound is promoted. Additionalembodiments further comprise, after step b) and prior to step c),sealing the enclosure to produce a sealed transformed cell-containingenclosure. Finally, some embodiments further comprise step d), coveringthe wound containing the transformed cell-containing enclosure with adressing.

In some embodiments, the systems, methods, kits, and compositions areused to treat skin conditions (e.g., of a human). In certainembodiments, the skin condition is selected from psoriasis, vitiligo,atopic dermatitis, or hyperproliferative or UV-induced dermatoses.

In further embodiments, the present invention provides a process formanufacturing a bioactive means for treating a wound-site, tumor, orother tissue in need of treatment comprising the steps of providing aplurality of substantially solid cell-support means; a biocompatibleenclosure means; a vehicle compatible with cell viability; and cells. Indifferent embodiments of the invention, the steps vary in sequence.

In other embodiments, the present invention provides means fordetermining, at various stages of manufacture, (i) the viability of thecells, (ii) the distribution of viable cells on each one of theplurality of solid-support means; (iii) the distribution of viable cellsas between the solid-support means and either the enclosure means or thevehicle; and (iv) the density of the cells on the solid cell-supportmeans.

In some embodiments, the present invention provides methods forpreparing an article comprising viable cells on an insoluble supportcomprising: a) providing an enclosure that is permeable to solutes; b)introducing into the enclosure an insoluble support material and sealingthe enclosure; and c) introducing viable cells into the enclosurewhereby the cells attach to the insoluble support material. In certainembodiments, the cells are injected into the enclosure. In otherembodiments, the enclosure comprises a mesh material and the injectionis performed through the mesh. In additional embodiments, the enclosurecomprises a septum and the injection is performed through the septum.

In particular embodiments, the methods of the present invention furthercomprise freezing the enclosure containing the viable cells. In otherembodiments, the methods further comprise thawing the enclosurecontaining the viable cells and maintaining the thawed enclosure in atissue culture medium. In additional embodiments, the methods furthercomprise testing the viability of the cells by staining the cells with adye that fluoresces upon binding of calcium and with a dye thatfluoresces upon intercalation into DNA, then measuring the ratio offluorescence of the calcium staining dye to the fluorescence of the DNAintercalating dye. In further embodiments, the methods further comprisetesting the viability of the cells by staining the cells with a dye thatfluoresces upon being hydrolysed by esterases (e.g. MDR1) and with a dyethat fluoresces upon intercalation into DNA, then measuring the ratio offluorescence of the esterase substrate dye to the fluorescence of theDNA intercalating dye. In other embodiments, mitochohdrial functionassays are employed.

In some embodiments, the present invention provides methods forpreparing an article comprising viable cells on an insoluble supportcomprising: a) providing an enclosure that is permeable to solutes butis impermeable to cells; b) introducing into the enclosure an insolublesupport material and then sealing the enclosure in a biocompatiblemanner; c) introducing viable cells into the sealed enclosure byinjection. In certain embodiments, the method further comprises testingthe viability of the cells by sampling the cells within the enclosureand staining the cells with a dye that fluoresces upon binding ofcalcium (or serving as an esterase substrate) and with a dye thatfluoresces upon intercalation into DNA, then measuring the ratio offluorescence of the calcium staining dye (or esterase substrate dye) tothe fluorescence of the DNA intercalating dye.

In particular embodiments, the present invention provides methods forpreparing an article comprising viable cells on an insoluble supportcomprising: a) providing an enclosure that is permeable to solutes andto cells; b) introducing into the enclosure an insoluble supportmaterial; c) immersing the enclosure containing the support materialinto a culture of viable cells, whereby the cells migrate into theenclosure and attach to the support material. In further embodiments,the method further comprises removing the enclosure from the culture andfreezing the article. In preferred embodiments, the support material istreated with a hydroxide solution prior to introducing the supportmaterial into the enclosure.

DESCRIPTION OF THE FIGURES

FIG. 1 diagrammatically depicts one embodiment of a tea bag contemplatedfor use with the cell-containing solid supports of the presentinvention.

FIG. 2 illustrates the condition of a tumor in a mouse, compared to acontrol, after treatment with one embodiment of the cell-containingenclosures of the present invention.

DEFINITIONS

To facilitate an understanding of the invention, a number of terms aredefined below.

As used herein, the term “tumor” refers to an abnormal growth thatarises from normal tissue, but that grows abnormally (e.g. abnormalgrowth rate and abnormal structure).

As used herein, the term “tumor regression” refers to any reduction inthe size of a tumor. Examples of tumor regression include, but are notlimited to, reducing the volume of a tumor by 5 percent, 10 percent, 20percent, 40 percent, 50 percent, 75 percent, and 100 percent. By“promoting” regression, it is meant that some regression is detectable(e.g. greater than 5% reduction in tumor mass). It is not intended thatthe term “promote” suggest that the tumor completely regresses. It issufficient that at least some regression is detectable.

The term “wound” refers broadly to injuries to tissue including the skinand subcutaneous tissue initiated in different ways, for example,surgery, (e.g., open post cancer resection wounds, including but notlimited to, removal of melanoma and breast cancer etc.), contained postoperation surgical wounds, pressure sores (e.g., from extended bed rest)and wounds induced by trauma. Wounds may also be classified into one offour grades depending on the depth of the wound: i) Grade I: woundslimited to the epithelium; ii) Grade II: wounds extending into thedermis; iii) Grade III: wounds extending into the subcutaneous tissue;and iv) Grade IV (or full-thickness wounds): wounds wherein bones areexposed (e.g., a bony pressure point such as the greater trochanter orthe sacrum). The term “partial thickness wound” refers to wounds thatencompass Grades I-III; examples of partial thickness wounds includeburn wounds, pressure sores, venous stasis ulcers, and diabetic ulcers.The term “deep wound” is meant to include both Grade III and Grade IVwounds.

The term “chronic wound” refers to a wound that has not healed within 30days.

The phrase “positioning the enclosure in the wound” is intended to meancontacting some part of the wound with the enclosure. The phrase“positioning the enclosure on the tumor” is intended to mean contactingsome part of a tumor with the enclosure. “Contacting” includes, but isnot limited to, bringing the enclosure proximate to the wound so as tobring the cells in fluidic communication with the wound.

The phrases “promote wound healing,” “enhance wound healing,” and thelike refer to either the induction of the formation of granulationtissue of wound contraction and/or the induction of epithelialization(i.e., the generation of new cells in the epithelium).

The phrase “wound fluid contents” refers to liquid associated with awound, as well as cells, cell factors, ions, macromolecules and proteinmaterial suspended in such liquid at the wound site.

The term “keratinocyte” refers to cells that produce keratin, ascleroprotein or albuminoid. Generally speaking, keratinocytes are foundin the epidermis or from cell lines derived from keratinocytes (e.g.,bacterial derived products).

The term “subject” refers to both humans and animals, including, but notlimited to, a dog, cat, bird, livestock, and preferably a human.Specific examples of “subjects” include, but are not limited to,individuals with tumors, such as individuals diagnosed with skin cancer.

The terms “enclosure,” “compartment,” and the like refer broadly to anycontainer capable of confining a cell-coated solid support within adefined location while allowing cellular factors to exit the enclosureinto the wound or tumor, and wound or tumor fluid contents to enter. Inpreferred embodiments, the enclosure is a sterile mesh pouch constructedof a woven, medical-grade polyethylene mesh. In one embodiment, thepresent invention contemplates a degradable enclosure (i.e., anenclosure that breaks down over time). In addition, the presentinvention contemplates the use of an enclosure constructed frommembranes. Preferably, after the solid support containing cells (e.g.,growing on the surface of the surface of the solid support or within thesolid support) is placed within the enclosure, the enclosure is sealedso as to prevent the solid support from exiting the enclosure. In oneembodiment, the sealed enclosure further comprises a transport means fortransporting cellular factors (e.g., outside of the enclosure and intothe wound). While the present invention is not limited to a particulartransport means, the transport means can include a means for applyingpressure (e.g, a pump).

The terms “a solid support”, “solid support”, and “solid supportmaterial” are used interchangeably, and refer broadly to any supportthat allows for cell growth, including, but not limited to, microcarrierbeads, gels, and culture plate inserts. Microcarrier beads suitable foruse with the present invention are commercially-available from a numberof sources, including, for example, Sigma, Pharmacia, and ICN. Inpreferred embodiments, the keratinocytes are grown on polyethylene bradsweighted by silica (e.g., CYTOLINE 1 macroporous microcarrier beads(Pharmacia Biotech). Culture plate inserts (i.e., cell support matricesthat generally comprise a membrane that supports cell growth) arecommercially available from, among other sources, CollaborativeBiomedical Products, Costar, ICN, and Millipore. In preferredembodiments, the culture plate inserts comprise a permeable microporousmembrane that allows free diffusion of ions and macromolecules.

The term “transplantable solid support” refers to a solid supportcontaining cells (e.g., keratinocytes, referred to as a“keratinocyte-containing solid support”) that can be placed within anenclosure. The enclosure containing the cell-containing solid supportmay then be placed in a wound to promote wound healing.

The phrases “means for removing,” “removal means”, “removal component”and the like refer broadly to any mechanism useful for assisting in thewithdrawal of a cell-containing enclosure from a wound (and/or theplacement of the cell-containing enclosure within a wound or on atumor). In some embodiments, the removal means or component comprises astring, thread, cord, or the like that is attached to the enclosure; inpreferred embodiments, the removal means or component is attached to agrasp that can be used as a handle to assist in the placement of thesolid support containing enclosure within the wound (or on a tumor) andits removal therefrom.

The term “dressing” refers broadly to any material applied to a woundfor protection, absorbance, drainage, etc. Numerous types of dressingsare commercially available, including films (e.g., polyurethane films),hydrocolloids (hydrophilic colloidal particles bound to polyurethanefoam), hydrogels (cross-linked polymers containing about at least 60%water), foams (hydrophilic or hydrophobic), calcium alginates (nonwovencomposites of fibers from calcium alginate), and cellophane (cellulosewith a plasticizer) [Kannon and Garrett, Dermatol. Surg., 21: 583-590(1995); Davies, Burns, 10: 94 (1983)]. The present invention alsocontemplates the use of dressings impregnated with pharmacologicalcompounds (e.g., antibiotics, anti-tumor compounds).

The term “biocompatible” means that there is minimal (i.e., nosignificant difference is seen compared to a control), if any, effect onthe surroundings. For example, in some embodiments of the presentinvention, the enclosure comprises a biocompatible membrane; themembrane itself has a minimal effect on the cells of the solid support(i.e., it is non-toxic and compatible with keratinocyte growth) withinthe membrane and on the subject (i.e., it has no advance impact on thesubject's health or the rate of wound healing) after the enclosure isplaced into a wound or on a tumor.

The term “extracellular matrix” refers broadly to material forsupporting cell growth. It is not intended that the present invention belimited by the particular material; the present invention contemplates awide variety of materials, including, but not limited to, material thatis distributed throughout the body of multicellular organisms such asglycoproteins, proteoglycans and complex carbohydrates. The presentinvention contemplates the use of a substratum of extracellular matrixwith the culture inserts on which the cells (e.g., keratinocytes) areplated. Although the present invention is not limited by the nature ofthe extracellular matrix, the preferred extracellular matrices includeMatrigel, Growth Factor Reduced Matrigel, fibrillar collagen, lamininn,fibronectin and collagen type IV.

The terms “transformed cell” or “transfected cell” refer to a cell thathas been transfected with a gene so that the protein encoded by the geneis expressed within the cell. In certain embodiments, the transfectedcell is stably transfected. In a preferred embodiment, the cell is asecretory cell and the protein encoded by the gene is excreted from thecell. Examples of secretory cells include, without limitation,fibroblasts, keratinocytes, endothelial cells, melanocytes, smoothmuscle cells, fetal fibroblasts and epithelial cells. It will beappreciated that more than one cell type, i.e., combinations of cells,may be employed. Cell lines (as opposed to primary cultured cells) mayalso be employed. It will be appreciated that a cell may be transfectedwith more than one gene so that more than one protein is expressed andexcreted. Methods for producing transformed cells, i.e. transfectionmethods, are known by those skilled in the art and include, withoutlimitation, the use of calcium phosphate coprecipitation,liposomemediated transfection, plasmid and viral vector-mediatedtransfection and DNA protein complex-mediated transfection and biolistic(e.g., gene gun) transfection. Viral vector mediated transfectionincludes, without limitation, the use of retroviral, replicationdeficient retroviral, adenoviral and adeno-associated viral vectors.Thus, a gene encoding a protein of interest may be introduced into acell where it is expressed and secreted from the cell. Examples of“proteins of interest” (and the genes encoding same) that may beemployed herein include, without limitation, cytokines, growth factors,chemokines, chemotactic peptides, tissue inhibitors ofmetallonproteinases, hormones, angiogenesis inhibitors, and apoptosisinhibitors. More specifically, preferred proteins include, withoutlimitation, EGF, VEGF, FGF, PDGF, IGF, KGF, IFN-α, IFN-δ, MSH, TGF-α,TGF-β, TNF-α, IL-1 and IL-6 [See also Table I and Myers et al. Am. J.Surgery, 170: 75-83 (1995), hereby incorporated reference].

As referred to herein, the term “encoding” is intended to mean that thegene or nucleic acid may be transcribed in a cell, e.g., when thenucleic acid is linked to appropriate control sequences such as apromoter in a suitable vector (e.g., an expression vector) and thevector is introduced into a cell. Such control sequences are well knownto those skilled in the art.

As defined herein “operatively-linked” means that the nucleic acid(i.e., gene encoding a protein of interest) and an expression controlsequence are situated within a vector or cell in such a way that theprotein of interest is expressed by a cell which has been transformed(transfected) with the ligated nucleic acid/expression control sequence.Expression control sequences are known to those skilled in the art [See,e.g., Goeddel, Gene Therapy Expression Technology: Methods in Enzymology185, Academic Press, San Diego, Calif. (1990)].

As used herein, the term “gene” means a nucleic acid which encodes aprotein or functional fragment thereof. The term “nucleic acid” isintended to mean natural and synthetic linear and sequential arrays ofnucleotides and nucleosides, e.g., in cDNA, genomic DNA (gDNA), mRNA,and RNA, oligonucleotides, oligonucleosides and derivatives thereof. Itwill also be appreciated that such nucleic acids can be incorporatedinto other nucleic acid chains referred to as “vectors” byrecombinant-DNA techniques such as cleavage and ligation procedures. Theterms “fragment” and “segment” as used herein with reference to nucleicacids (e.g., cDNA, genomic DNA, i.e., gDNA), are used interchangeably tomean a portion of the subject nucleic acid such as constructedartificially (e.g. through chemical synthesis) or by cleaving a naturalproduct into a multiplicity of pieces (e.g. with a nuclease orendonuclease to obtain restriction fragments). The term “polypeptide” isused to mean three or more amino acids linked in a serial array.

As used herein the term “portion” when in reference to a nucleotidesequence (as in “a portion of a given nucleotide sequence”) refers tofragments of that sequence. The fragments may range in size from fournucleotides to the entire nucleotide sequence minus one nucleotide (10nucleotides, 20, 30, 40, 50, 100, 200, etc.).

The term “recombinant DNA molecule” as used herein refers to a DNAmolecule that is comprised of segments of DNA joined together by meansof molecular biological techniques.

The term “recombinant protein” or “recombinant polypeptide” as usedherein refers to a protein molecule that is expressed from a recombinantDNA molecule.

As used herein, the term “vector” is used in reference to nucleic acidmolecules that transfer DNA segment(s) from one cell to another. Theterm “vehicle” is sometimes used interchangeably with “vector.”

The term “expression vector” as used herein refers to a recombinant DNAmolecule containing a desired coding sequence and appropriate nucleicacid sequences necessary for the expression of the operably linkedcoding sequence in a particular host organism. Nucleic acid sequencesnecessary for expression in prokaryotes usually include a promoter, anoperator (optional), and a ribosome binding site, often along with othersequences. Eukaryotic cells are known to utilize promoters, enhancers,and termination and polyadenylation signals.

DESCRIPTION OF THE INVENTION

The present invention relates to devices, systems and methods fortreating tumors. In particular, the present invention relates toenclosures housing cell-coated supports for promoting regression oftumors, such as cancerous tumors, papillomas, and warts. The presentinvention also relates generally to tissue healing and regeneration and,more particularly, to methods and systems for wound healing.

In preferred embodiments, the present invention provides methods ofpromoting tumor regression employing enclosures secreting therapeuticproteins. In certain embodiments, the enclosures house solid supportmaterial containing cells that are transfected with a gene encoding thetherapeutic protein or proteins. One example of the tumor regressionpromoting abilities of the enclosures of the present invention isprovided in Example 6. In this example, viable cells on solid supportmaterial are transfected with a gene encoding IL-1 and placed in anenclosure. The enclosure is placed on a tumor and promotes regression inthe size of the tumor. Importantly, the enclosures of the presentinvention are capable of delivering therapeutic proteins for promotingtumor regression in an ex-vivo manner, thus avoiding the toxic affectsmany proteins have when delivered systemically. In certain embodiments,the therapeutic protein directly promotes tumor regression. In otherembodiments, the therapeutic protein stimulates cells surrounding thetumor causing these surrounding cells to reduce the size of the tumor.In further embodiments, the therapeutic protein also stimulates aninflammatory response to help remove bacteria or other infectious,organisms.

In other embodiments, the present invention involves the unique use ofcultured cells to treat wounds, including post surgical wounds (e.g.,open post cancer resection wounds and contained post operation surgicalwounds) and chronic wounds (e.g, diabetic wounds). In preferredembodiments, cultured cells grown on transplantable solid supports areplaced in a permeable enclosure; the enclosure is then placed in awound. The cultured cells may be any cell type, including keratinocytesand/or transformed cells. Though a precise understanding of how the cellcontaining enclosure effects wound healing is not required in order topractice the present invention, it is believed that the cells in theenclosure secrete certain factors that enhance wound healing. Theusefulness of the present invention has been demonstrated in athymicnude mice, an animal model routinely utilized in wound closure testing[See, e.g, Boyce et al., Surgery, 110: 866-76 (1991); Barbul et al.,Surgery, 105: 764-69 (1989); and Hansbrough et al., J. Burn CareRehabil., 14: 485-94 (1993)].

It will be appreciated that the transformed cells of the presentinvention are not limited by the nature of the cells utilized nor by thegenes employed to transform the cells. Examples of cells include, butare not limited to, the cells set forth in Table 1. TABLE 1 Cytokine,Growth Factor, Wound CELL Made/Responds Healing TYPE TISSUE To MatrixInteractions Potential Fibroblast Dermis TGF-beta, PDGF, Collagen typeI, III, and Fibroblast +4 Viseral IGF, IL-1, FGF, IV, Elastin,Fibronectin, Organs CTGF nidogen, SPARC, Osteonectin, Protenglycons,glucosamino-glycons, collagenases, gelatinase, stromelysin, TIMP,Thrombospondin Endothelial Blood Vessels FGF, VEGF, TIMP, GAG, Elastin,Endothelial Cell Endothelin, IGF, Laminin, Collagenase, Cell +4 IL-1Type IV Collagens, Fibronectin Melanocyte Dermis IL-1, MSH No ECMProduction Melanocyte +1 Smooth Blood Vessels PGDG, IGF, EGF, TIMP, GAG,Elastin, Fetal Muscle Cell FGR Laminin, Collagenase, Fibroblast +4Collagens, Fibronectin Epithelial Cell Dermis FGF, TGF-alpha, TIMP, GAG,Elastin, Epithelial Mucosa TGF-beta, PDGF, Laminin, Collagenase, Cell +4IGF, IL-1, EFG, Collagen type IV, VI, VII, FGF, KGF IFN- laminins,Fibronectin, gammama, TNF- epiligrin, nidogen, elastin, alpha, IL-1alpha, tenascin, thrombospondin, activin GAGs, proteoglycons, EMMPRIN,SPARC, uPA, PAI, collagenase, gelatinase, stromelysin

Abbreviation Glossary Cytokine, Growth Factors Made/Respond To MatrixInteractions TGF Transforming Growth Factor TIMP Tissue Inhibitor ofMetalloprotoinases PDGF Platelet Derived Growth Factor GAG GlucoseAminoglycons IGF Insulin-like Growth Factor SPARC Secreted ProteinAcidic and Rich in Cysteine IL Interleukin ECM Extracellular Matrix FGFFibroblast Growth Factor EMMPRIN Extracellular Matrix MetalloproteinaseCTGF Connective Tissue Growth Factor Inducer VEGF Vascular EndothelialGrowth Factor uPA Urokinase Type Plasminogen Activator MSH MelanocyteStimulating Hormone PAI Plasminogen Activator Inhibitor EGF EpidermalGrowth Factor KGF Keratinocyte Growth Factor IFN InterferonI. Sources of Cells

The present invention is not limited by the source of the cells used,such as keratinocytes. In some preferred embodiments, the cells areobtained from living donors undergoing breast operations. In certainembodiments, prior to their use, the cells obtained from the donors arearchived for at least six months, after which they are tested for thepresence of viruses (e.g., hepatitis virus and HIV). In other preferredembodiments, the cells are cadaveric in origin. After the cells havebeen harvested from the cadaver, they are screened for viruses and othermicrobes prior to use.

Generally speaking, the keratinocytes contemplated for use with thepresent invention are primary cultured cells (i.e., the cells are notderived from cell lines) or are cells that have been transfected anddeveloped into a keratinocyte derived cell line.

Example 1 in the Experimental section illustrates one embodiment of howkeratinocytes may be isolated and processed for use with the presentinvention. However, it should be noted that the present invention is notlimited to primary cultured cells.

Moreover, the present invention contemplates the use of cells that havesimilar characteristics to keratinocytes (e.g., cells that secretegrowth factors, cytokines or keratin, whose behavior the cells utilizeto promote wound healing). As described in detail herein, these cellsmay be derived from cells that are not keratinocytic in origin but havebeen modified by recombinant techniques, i.e. transformed cells.

II. Growth of Cells on Solid Supports

The cells contemplated for use with the present invention (e.g.,keratinocytes and transformed cells) are grown on transplantable solidsupports (solid support material). The present invention contemplatesthe growth of cells on solid supports, including protein-coated solidsurfaces, as has been described in the art. For example, Gilchrest etal. [Cell Bio Int. Rep. 4: 1009 (1980)] describe the growth ofkeratinocytes on fibronectin-coated plates in the absence of a 3T3monolayer, while Schafer et al. [Exp. Cell. Res. 183: 112 (1989)]describe a study of keratinocytes on floating collagen gels.Furthermore, Cook and Buskirk [In Vitro Cell Dev. Biol. 31: 132 (1995)]describe the growth of keratinocytes on a variety of matrices, includingmicroporous membranes coated with collagen.

The present invention is not limited by the nature of the solid support.Indeed, the methods of the present invention may be practiced inconjunction with any support material that allows for cell growth,including, but not limited to, microcarrier beads, gels, and cultureplate inserts. When microcarrier beads are desired, suitable beads arecommercially available from a number of sources; for example, Sigmasells both collagen-and gelatin coated beads, Pharmacia sellsdextran-based beads, and ICN advertises collagen beads. In preferredembodiments, the keratinocytes are grown on polyethylene beads weightedby silica (e.g., CYTOLINE 1 macroporous microcarrier beads (PharmaciaBiotech)).

Furthermore, culture plate inserts (i.e., cell support matrices thatgenerally comprise a membrane that supports cell growth) arecommercially available from, among other sources, CollaborativeBiomedical Products, Costar, ICN, and Millipore. Such inserts frequentlycomprise polyethylene terephthalate, polycarbonate, TEFLON (Gore), andmixed cellulose esters. In particular embodiments, the culture plateinserts comprise a permeable microporous membrane that allows freediffusion of ions and macromolecules.

As indicated above, the present invention contemplates the use oftransplantable solid supports. More specifically, in some embodiments,the present invention contemplates the application ofkeratinocyte-coated and transformed cell-coated solid supports, housedin an enclosure, to wounds and tumors. The use of cell-coatedtransplantable solid supports for application to wounds has beendescribed in the art. For example, Hansbrough et al., J. Am. Med. Assoc.262: 2125 (1989), describe collagen-glycosaminoglycan membranes coveredwith keratinocytes for wound application. [See also, Cooper et al., J.Surg. Res., 48: 528 (1990); Ronfard et al. Burns, 17: 181 (1991); Tinoiset al., Exp. Cell Res., 193: 310 (1991); and Nanchahal and Ward, Brit.J. Plas. Surg. 45: 354 (1992)].

Generally speaking, growth of keratinocytes and other“anchorage-dependent cells requires attachment to a surface andspreading out in order to grow. Coventionally, such cells have beencultured on the wall of non-agitated vessels (e.g. tissue cultureflasks) and roller bottles (e.g. U.S. Pat. No. 5,512,474, herebyincorporated by reference). Though not limited by the manner in whichthe cells are grown on solid supports, the present inventioncontemplates the use of these conventional techniques for growing cellson solid supports (see Example 1).

Other techniques for culturing solid support-bound cells arecontemplated for use with the present invention. In some embodiments,the present invention contemplates the use of bioreactors for cellgrowth (See, U.S. Pat. No. 5,459,069 to Palsson et al., U.S. Pat. No.5,563,068 to Zhang et al., both of which are hereby incorporated byreference.). Some bioreactors utilize hollow fiber systems. Frequently,bundles of parallel fibers are enclosed in an outer compartment; cellsare grown on the outside surface of the fibers, while nutrient andgas-enriched medium flows through the center of the hollow fibers,nourishing the cells [See, e.g, U.S. Pat. No. 5,512,474 to Clapper etal., herein incorporated by reference].

In addition, bioreactors utilizing microcarriers (e.g., DEAE-derivativeddextran beads) can be used in conjunction with the present invention. Insome embodiments, cell adhesion proteins like collagen, fibronectin, andlaminin are used to anchor the cells to the solid support. Microcarriersmay also incorporate an ionic charge to assist in cell attachment to themicrocarrier. Frequently, the microcarriers are porous beads that aresufficiently large to allow cells to migrate and grow in the interior ofthe bead [See U.S. Pat. No. 5,512,474 to Clapper et al., herebyincorporated by reference].

In a particularly preferred embodiment, cells, are supported on a rigidsupport matrix (a semipermeable membrane) which allows for celladherence and growth. The cells form a dense, three-dimensional arraywith large surface area which enhances modification of the fluid phasebathing the cells; the cell-populated matrix is constantly exposed towound fluid components which diffuse into the reactor. The fluid can bemodified and/or the cells can secrete mediators into the fluid tooptimize the wound environment.

III. Enclosures

The present invention contemplates the placement of cell-coated (e.g.,keratinocyte-coated) solid supports (e.g., beads) and transformedcell-coated solid supports (e.g., beads) in an enclosure, which, inturn, is placed in a wound or on a tumor. In preferred embodiments, theenclosure is a sterile mesh pouch constructed of a woven, medical-gradepolyethylene mesh. Though not limited to mesh materials manufactured byany particular company, Tetko, Inc. and Saati manufacture mesh materialssuitable for use with the present invention. The enclosures of thepresent invention may be colored or otherwise marked so that they may beeasily identified in a wound or on a tumor.

Of course, other suitable materials (e.g., nylon, or other polymers) mayalso be used and are within the scope of the present invention. Indeed,any material that exhibits biocompatiblity when placed within a wound,or on a tumor, may be used with present invention. In addition, thepresent invention contemplates the use of an enclosure constructed frommembranes, including the membranes sold commercially by Gelman Sciencesand Millipore.

In a preferred embodiment, the enclosures are assembled as pocket-likecontainers with four edges and two surfaces. These containers may bemanufactured in many ways (see, e.g., “Constructing Enclosures” sectionbelow). For example, the enclosure may be created by welding (e.g.,uniting to create a seal) two pieces of material (of approximately equaldimensions) together on three edges. The fourth edge is left open toallow filling of the enclosure with the cell coated beads. The fourthedge is then sealed.

In an alternative embodiment, the enclosure may be manufactured from onepiece of material by first folding that piece of material back ontoitself. The region where the material overlaps itself may then bewelded, resulting in the formation of a cylindrical tube. Thereafter, apocket can be formed by welding closed one of the open ends of thecylinder, leaving the other end open for filling with the cell-coatedbeads; this enclosure design has the advantage of requiring one lessweld.

The present invention is not limited to enclosures assembled asfour-edged pockets nor is the invention limited to the techniques ofconstructing the enclosures disclosed above. For example, trapezoidal orcircular enclosures may also be used in conjunction with the presentinvention.

For the assembly of the enclosures, the present invention contemplatesuse of a variety of sealing techniques, including ultrasonic welding orheat welding. The technique of ultrasonic welding is well-known in themedical device-manufacturing art [See, e.g, U.S. Pat. Nos. 4,576,715 and5,269,917, hereby incorporated by reference]. The present invention isnot limited to a particular welding/sealing technique; indeed, anysuitable sealing technique may be used with the present invention,including but not limited to ultrasonic, radiotrequency, heat, andimpulse sealing.

In those embodiments comprising a mesh enclosure, the present inventionis not limited by the pore size of the mesh. However, it should be notedthat extremely small pores may retard or preclude the movement ofmaterials out of the enclosure. The preferred range of pore sizes isfrom about 10 microns to about 300 microns. In particularly preferredembodiments, the pore size is about 300 microns (e.g., 290-310 microns).Likewise, if a membrane is used, the membrane should be permeable to theextent that it allows the cell factors to cross the membrane into thewound or onto a tumor.

In preferred embodiments, the solid support-containing enclosures of thepresent invention are configured like tea-bags (See, FIG. 1). That is,one end of a handle (3) (e.g., a biocompatible nylon material or excessfrom a heat seal, wire, etc.) is attached to the enclosure (1) housingthe solid support (4), while the other end of the string is attached toa grasp (2). The grasp (2) is used as a “handle” to assist in theplacement of the solid support-containing enclosure within the wound, oron a tumor, and its removal therefrom. The present invention is notlimited by the material used to construct the grasp; in preferredembodiments, the grasp component (2) comprises a medical gradepolyethylene material. Generally speaking, the grasp (2) is taped to thesubject's skin at a site external to the wound. The solid support (4)has cells (e.g., keratinocytes) attached; it is preferred that suchcells are viable.

IV. Transfer of Cell Factors

Following placement of the enclosure within the wound, or on a tumor,the cell factors including proteins of interest (e.g, growth factorslike epidermal growth factor, cytokines, PGDF, insulin like growthfactor, TGF-beta, keratinocyte growth factor cytokine, TNF, chemokines,chemotactic peptides, tissue inhibitors of metalloproteinases, etc.)secreted from the cells (e.g., keratinocytes and transformed cells) passthrough the enclosure and into the wound, or onto a tumor. The inventorsof the present invention have found that it is not necessary of thecells to be in direct contact with the wound. Though an understanding ofwhy such indirect contact is sufficient for wound healing is notrequired in order to practice the present invention, it is believed thatthe donor cells (i.e., those contained within the enclosure) create afavorable environment for growth of the keratinocytes present in thewound of the subject. Thus, the keratinocytes from the healed wound siteare thought to be of recipient, rather than donor, origin [See Van derMerve et al., Burns, 16: 193 (1990)]. In addition, the cells mayactively modify wound fluid characteristics or components (e.g.,modulating proteolytic activity to optimize the wound environment).

The inventors of the present invention discovered empirically thatplacement of cell-coated solid supports within the enclosures (describedabove) resulted in good size reduction of deep wounds; in comparison,researchers previously reported less than ideal healing in deeper wounds[Van der Merve et al., Burns 16: 193 (1990)] when other techniques wereused.

The inventors have found that the use of the present invention inconjunction with standard wound dressing materials does not adverselyaffect the ability to modify the wound environment. For example, afterplacing the keratinocyte-containing enclosures or transformedcell-containing enclosures within a wound, the enclosure can itself becovered with occlusive dressings such as hydrogels, foams, calciumalginates, hydrocolloids, and films. Example 2 of the Experimentalsection addresses an embodiment wherein a keratinocyte-containingenclosure is covered by a wound dressing.

V. Therapeutic Proteins and Genes

As mentioned above, the present invention contemplates transfectingcells with nucleic acid sequence (e.g. at least a portion of a humangene sequence), such that the cells express at least one therapeuticprotein for promoting wound healing or treating tumors (e.g. promotingtumor regression). In some embodiments, the cells are transfected withat least one type of cytokine gene. Examples of cytokine genes (withcorresponding GENBANK accession numbers) include, but are not limitedto, interleukin-1 (alpha, NM_(—)000575; beta, NM_(—)000576),interleukin-2 (NM_(—)000586), interleukin-4 (NM_(—)000589),interleukin-6 (NM_(—)000600), interleukin-7 (NM_(—)000880),interleukin-10 (NM_(—)000572), interleukin-12 (12A, NM_(—)000882; 12B,NM_(—)002187), interferon-alpha (NM_(—)024013), interferon beta(NM_(—)002176), interferon-delta, tumor necrosis factor alpha(NM_(—)000594) and beta (NM_(—)009588), granulocyte-macrophage colonystimulating factor (GM-CSF); and granulocyte colony stimulating factor(G-CSF).

Nucleic acid sequence which inhibit expression of oncogenes such asHER-2/neu (e.g., the tumor suppressor E1A from adenovirus 5), or whichcontrol cell growth or differentiation are also preferred fortransfecting cells of the present invention. For example, nucleic acidswhich encode expression of inflammatory molecules, cytokines, growthfactors, telomerase, growth factor receptors, oncogene products,interleukins, interferons, alpha-FGF, IGF-I, IGF-II, beta-FGF, PDGF,TNF, TGF-alpha, TGF-beta, EGF, KGF, SCF/c-Kit ligand, CD40L/CD40,VLA-4/VCAM-1, ICAM-1/LFA-1, and hyalurin/CD44; signal transfectionmolecules and corresponding oncogene products, e.g., Mos, Ras, Raf, andMet; and transcriptional activators and suppressors, e.g., p53, p21,Tat, steroid hormone receptors such as those for estrogen, progesterone,testosterone, aldosterone, and corticosterone or the like are known,preferred, and widely available. Nucleic acids which encode inhibitorsof such molecules are also preferred, such as ribozymes and anti-senseRNAs which recognize and inhibit translation of the mRNA for any of theabove.

In further embodiments, the cells of the present invention aretransfected with tumor suppressor genes. Examples of tumor suppressorgenes include, but are not limited to, APC, BRCA1, BRCA2, CDH1, CKKN1C,CDKN2A, CYLD, EP300, EXT1, EXT2, MADH4, MAP2K4, MEN1, MLH1, MSH2, NF1,NF2, PRKAR1A, PTCH, PTEN, RB1, SDHD, SMARCB1, STK11, TP53, TSC1, TSC2,VHL, WT1, or combinations thereof.

VI. Tumor Susceptibility Assays

The present invention also provides tumor susceptibility assays.Preferably, the tumor susceptibility assays of the present invention areemployed to help select one or more therapeutic proteins likely topromote tumor regression in particular tumors. In this regard, the cellsof the present invention may be transfected with a nucleic acid sequenceor sequences encoding a therapeutic protein likely to be useful inpromoting tumor regression for specific tumors. The tumor susceptibilityassays allow, for example, the enclosures of the present invention to be“customized” for a particular patient, thus improving the effectivenessof the tumor treating abilities of the enclosures of the presentinvention.

In certain embodiments, tumor susceptibility assays are performed bysurgically removing a portion a subject's tumor, and growing a least aportion of the tumor in culture. The explanted tumor culture may thenexposed to solid support material (e.g. beads) containing cellsexpressing one or more candidate therapeutic proteins (e.g. cellsexpressing one or more cytokines). Inhibition, or non-inhibition, of thetumor cells is then detected. In preferred embodiments, a least aportion of the subject's tumor is grown in tissue culture media. Inother preferred embodiments, a primary culture is established with thetumor cells prior to further manipulation. In some preferredembodiments, the cells on the solid support material expressing thecandidate therapeutic protein are mouse macrophage cells. In certainembodiments, the solid support (e.g. beads) populated with transfectedcells are primed using culture media from the tumor of being assay. Inother embodiments, the solid support material populated with transfectedcells are co-cultured with the tumor cells.

In particular embodiments, the present invention provides methodscomprising, a) providing; i) viable cells on a solid support, whereinthe viable cells secrete at least one candidate therapeutic protein, ii)a tumor sample comprising cancer cells, wherein the tumor sample isderived from a subject's tumor, b) contacting the viable cells with thetumor sample under conditions such that the cancer cells' susceptibilityto the candidate therapeutic protein is determined. In some embodiments,a control is also run where viable cells not secreting a therapeuticprotein (e.g. not transfected with a nucleic acid sequence encoding thetherapeutic protein) are assayed in the same manner as the viable cellsthat are secreting a candidate therapeutic protein. In preferredembodiments, once cells (on solid support material) are identified aslikely to cause tumor regression/destruction, this type of cell ispackaged into the enclosures of the present invention and employed onthe subject's tumor or tumors (e.g. contacted with the subject's tumorsfor 2 hours, 4 hours, 12 hours, 24 hours, 2 days, a week, etc).

In particular embodiments, the subject's tumor is not removedsurgically, and instead, a enclosure of the present invention containingsolid support material with cells expressing a candidate therapeuticprotein is contacted directly with the subject's tumor. In similarembodiments, the tumor cells are grown in an immuno-incompetent testanimal (generating a tumor), and the enclosure is contacted with thetumor directly (See, Example 7). In certain embodiments, the ability ofthe enclosure (containing the cells secreting the candidate therapeuticprotein) is determined by removing the enclosure from the tumor after aperiod of time (e.g. one day, two days, one week, etc.). Theeffectiveness of the enclosure in promoting tumor regression may bedetermined by examining either the tumor (e.g. to see if it has reducedin size), or examining (or further manipulating) the enclosure. Forexample, as shown in Example 7 below, the amount of tumor cells thathave invaded the solid support material may be examined.

The ability of the enclosure to promote tumor regression may beestablished, for example, if tumor cells are unable to significantlyinvade the solid support material. Conversely, if tumor cells are ableto invade the solid support material, even in the presence of the cellssecreting the candidate therapeutic protein, it is unlikely that theenclosure will promote significant tumor regression. However, this willinform the user that a different candidate therapeutic protein shouldlikely be assayed in an attempt to identify therapeutic proteins (andenclosures) for particular patients.

Tumor susceptibility to a particular treatment may also be determined byperforming DNA or RNA diagnostic assays on a patient's normal cells ortumor cells. In this regard, variations in a particular subject's tumorsor normal cells may be employed to selected nucleic acid sequencesencoding proteins likely to be useful in promoting tumor regression.Specific methods for nucleic acid variation detection include DNAsequence determination (Sanger method with either radionuclide orfluorescence label, Maxam and Gilbert Method, HPLC, or other methods)through use of manual, semi-automated, or automated processes includinguse of gels or capillaries, Mass Spec-based technologies includingMALDI-TOF MS, spectral assays, technologies aimed at detection ofdifferent melting temperatures for sequences that differ from eachother, technologies based on use of confocal or de-convolutingmicroscopy to evaluate fluorescence labeled DNA, RNA, or DNA/RNAhybrids, via affinity sensor using surface plasmon resonancetechnologies, PCR and RT-PCR, use of other clone-based,polymerase-based, or PCR based technologies to detect hybridization insimplex or multiplex technologies, electronically active microfabricatedarray technologies such as APEX microchips, electrical fielddenaturation, microplate array diagonal gel electrophoresis (MADGE),amplification including TAQMAN technologies, measurements ofsequence-base changes in electron transfer through the DNA helix,gene-chip assays involving high density oligonucleotide arrays includingAffymetrix-like technologies, microarray technologies, ribotyping,pulsed-field gel electrophoresis (PFGE), field alternation gelelectrophoresis (FAGE) and related technologies, allele-specific ordifferential PCR amplification, hybridization-based technologiesincluding Southerns, Northerns, dot-blots and slot-blots, double- ortriple-helix formation, dual-label fluorescence assays of differentialhybridization of DNA, amplified fragment length polymorphism-basedfingerprinting (AMF), confirmation variation based technologies such assingle strand confirmation polymorphism (SSCP) or GC-clamped denaturinggradient gel electrophoresis or other variations on this concept thatevaluate conformational differences in DNA, RNA, or DNA/RNA hybridstructures, other rapid scanning technologies based on screening forsequence mismatches through detection of DNA, RNA, or DNA/RNA hybridscontaining mismatched or altered base-pairing including use of alteredmobility through capillaries or acrylamide-based, agarose based, MDE orother forms of gel technology, additional rapid scanning technologiesbased on detection of DNA, RNA, or DNA/RNA hybrids with mismatched oraltered base pairing via cleavage at, or other form of digestion of thetarget through either enzymatic or chemical methods, or polymerase-basedextension from, mismatched or altered base pairing of DNA, RNA, orDNA/RNA hybrids, primer-extension-based technologies, allele specificoligonucleotide hybridization, or cutting of cloned or PCR-amplifiedsegments of the gene with restriction enzymes. This use of sequences inscreening includes not only use of coding sequences but also use ofintronic sequences, flanking portions of unprocessed and processedtranscripts, adjoining regions including promoters and other sequences3′ and 5′ to the gene. For a review of detection methodologies, see Shi,Clinical Chemistry, 47:2, 164-172 [2001], discussing, for example,TAQMAN, Rolling Circle, and INVADER assays, this review herebyincorporated by reference, see also, U.S. Pat. Nos. 6,150,104 and6,210,884 for suitable detection methods, both of which are herebyincorporated by reference.

Examples of subject's tumors that may be assayed include, but are notlimited to, any solid tumor, melanoma, breast, pancreas, colon, stomach,bladder, ovary, bone, kidney sarcomas or carcinomas. The subject's tumorthat is surgically removed may, for example, be either recurrent orprimary.

Any method may be used to determine the affect (e.g. inhibition ornon-inhibition) of the transfected cells on the tumor. In someembodiments, inhibition of the tumor is determined using a lines ofgrowth inhibition assay, or an examination invasion of the solid supportby tumor cells, or by death of the tumor culture.

In certain embodiments, the present invention provide kits comprisingtwo or more components useful for performing tumor susceptibilityassays. In certain embodiments, the kits comprise instructions forperforming a tumor susceptibility assay, and one other component (e.g.enclosures, solid support material, cells configured for secreting oneor more therapeutic proteins, etc.).

VII. Constructing Enclosures

The present invention also provides methods for constructing enclosures.U.S. Provisional Application 60/149,744, and U.S. patent applicationSer. No. 09/640,990, both of which are hereby incorporated by referencefor all purposes, describe methods of making enclosures useful in thepresent invention. Enclosures and methods of making enclosures are alsoprovided, for example, in U.S. Pat. No. 5,972,332, as well as U.S.patent application Ser. Nos. 09/323,188 and 09/502,479, all of which arehereby incorporated by reference for all purposes.

In constructing enclosures, any solid-support means capable ofsustaining a living cell (e.g., within the meaning of the viability testdisclosed herein) may be selected for use by the skilled practitioner ofthis invention. In preferred embodiments, solid supports will beselected to provide adequate surface area to accommodate cell attachmentand growth to a sufficiency for the purposes of the invention. Inpreferred embodiments, solid supports will be selected to be of such ashape and size as to be substantially incapable of permeating theselected enclosure. It is not intended, however, that suchimpermeability be achieved solely by the shape or size of the solidsupports. Other properties, such as the degree of hydrophilicity andhydrophobicity, the electrical charge properties, and the lipophilicityor polarity of either the solid supports or the enclosure means may alsobe employed to achieve the preferred impermeability.

In some embodiments, to promote cell-seeding and/or cell viability,solid-support material is treated or coated with biocompatiblesubstances to render them more or less hydrophilic or hydrophobic,cationic or anionic, polar or non-polar are also contemplated to bewithin the scope of this invention.

Any biocompatible enclosure means (material) capable of substantiallyretaining the selected cell-support means (material) may be selected bythe skilled practitioner of this invention. P530 Natural (AET, Inc.) isa specific example. In preferred embodiments an enclosure means that isgenerally permeable to solutes will be selected. In certain embodimentsan enclosure means that is permeable to cells in at least one directionwill be preferred. In certain embodiments enclosure means that resistattachment of cells to one or both of their surfaces are preferred. Incertain embodiments, the enclosure means is sealable in such a way thata biocompatible seal results. In certain embodiments, the skilledpractitioner will select an enclosure means and a sealing means suchthat the enclosure means and the seal remain useful for the purposes ofthe invention after being subjected to temperatures adequately high tosterilize the enclosure means or adequately low to preserve cellviability by means of freezing.

The properties enumerated in the foregoing are exemplary and, ingeneral, do not need to be combined in any particular aggregation toeffect a useful embodiment of the invention. Thus, cells may beintroduced into a pre-sealed enclosure by means of injection or byeffecting immigration of cells through a cell-permeable enclosure means.Alternatively, cell-support means and cells may be introduced into asealably open enclosure. The cell support means, moreover, need not beseeded with cells when the cell support means is introduced into theenclosure. Indeed, embodiments are contemplated wherein at least aportion of the cell-support means and at least a portion of the cells ineach manufactured article are introduced into, and reside in, theenclosure in separate compartments. Compartmentalization may be achievedby a physical barrier such as a membrane, or by segregating the supportmeans and the cells in separate vehicles, which vehicles are renderedimmiscible by virtue of having been frozen separately, or suspended inimmiscible gels. The skilled practitioner may select from a number ofcell culture media known to support cell growth. The selection, forwhich the skilled practitioner will have ample guidance from the priorart, will depend upon the cell-type and specific conditions chosen toprepare the cell culture.

Generally, the selection of cells depends upon the bioactive treatmentintended. For example, keratinocytes derived from breast tissue,foreskin, abdominal full or split thickness skin, or the skin ofcadavers are useful in the treatment of wounds. Other acceptable primarycell types include, without limitation, fibroblasts, melanocytes,endothelial cells, blood-borne cells, and osteocytes. Any celltransformed by the insertion of DNA by any means that results in a cellcapable of secreting an expression product of the inserted DNA, or aproduct whose expression by the cell is promoted or enhanced by theinsertion of the DNA is also suitable. The particular DNA to be selectedwill depend upon the treatment to be applied. An ample literature existsto provide guidance to the skilled practitioner in this regard. Inpreferred embodiments, the cells are transfected after being seeded onto the solid support material.

In some embodiments, a cell viability assay is performed on the cells.In certain embodiments, the cell viability assay is performed before thecells are seeded onto the solid support material. In other embodiments,a cell viability assay is performed after the cells are seeded on thesolid support material. In preferred embodiments, a cell viability assayis performed after the cells on the solid support are placed in anenclosure. Any type of cell viability assay may be used with the presentinvention. In some embodiments, the cell viability assay comprises amitocondrial function assay.

VIII. Enclosures with Monitoring Devices

In certain embodiments, the enclosures of the present invention contain,or are otherwise attached to, one or more monitoring devices. Thesedevices may be used with the enclosures of the present invention tomonitor the status of the condition being treated by the enclosure. Forexample, in addition to the enclosure contacting a wound or tumor, themonitoring device may also contact the wound or tumor. In this regard,the progress of treatment (e.g. promotion of wound healing, or tumorregression) may be monitored without the need for visual inspectionand/or other medical tests. This allows both constant monitoring, andreduces the need for the subject (or the subject's physician) to removethe enclosure to inspect the wound, tumor, or other condition.

The monitoring device may be any device capable of collectinginformation about a subject's condition (e.g. size of wound or tumor,temperature of subject, ion concentrations, pH, etc), and displayingthis information (e.g. on a LCD display, or by transmitting thisinformation to a receiver). In preferred embodiments, the informationcollected by the monitoring device is transmitted over the Internet tothe subject's physician or other health care professional. Examples ofmonitoring devices are provided in U.S. Pat. No. 4,763,659 to DunsearthJr., U.S. Pat. No. 6,070,103 to Ogden, and U.S. Pat. No. 5,836,989 toShelton, all of which are herein incorporated by reference for allpurposes. In certain embodiments, the cells (on the solid supports) inthe enclosures are modified (e.g. with a reporter or recorded gene) inorder to work with the monitoring device. In a preferred embodiment, theenclosures of the present invention can be attached to monitoringdevices comprising electronic sensors and placed into a skin wound. Inother preferred embodiments, the electronic sensors can determinetemperature, viscosity, lactic acid, pH, Na+ K+, oxygen, specificgravity, or other wound products known to be toxic to the wound.

Experimental

The following examples are provided in order to demonstrate and furtherillustrate certain preferred embodiments and aspects of the presentinvention and are not to be construed as limiting the scope thereof.

In the experimental disclosure which follows, the followingabbreviations apply: N (normal); M (molar); mM (millimolar); μM(micromolar); mol (moles); miol (millimoles); μmol (micromoles); nmol(nanomoles); pmol (picomoles); g (grams); mg (milligrams); μg(micrograms); ng (nanograms); l or L (liters); ml (milliliters); μl(microliters); cm (centimeters); mm (millimeters); μm (micrometers); nm(nanometers); DS (dextran sulfate); C (degrees Centigrade); and Sigma(Sigma Chemical Co., St. Louis, Mo.).

EXAMPLE 1

The experiments of this example demonstrate that human culturekeratinocytes grown on macroporous microcarriers and contained in aporous enclosure improve healing in surgically created wounds in mice.

A. Experimental Methodology

Preparation of Human Keratinocytes

Isolation and Growing of Human keratinocytes: Human keratinocytes (AATBcertified; University of Michigan cultured keratinocyte program) wereisolated at The University of Michigan Burn/Trauma Unit from splitthickness skin.

Trypsinization of the split thickness skin was effected as follows. Theskin was placed dermis-side down in 150 mm Petri dishes. The pieces werecut into smaller pieces (about 2 cm×about 0.3 cm) and were soaked in asterile solution of 30 mM HEPES, 10 mM glucose, 3 mM KCl, 130 mM NaCl, 1mM Na₂HPO₄ buffer, pH 7.4 containing 50 units of Penicillin and 50 μgStreptomycin (Sigma, P-0906). After soaking for 1-2 hr at 4° C. thebuffer was aspirated off, and 0.09% trypsin (Sigma, Type IX) in aPenicillin and Streptomycin buffer was added to the dishes containingthe skin tissue.

After trypsinizing overnight at room temperature, the enzyme solutionwas aspirated off, and complete MCDB 153 (Gibco, Grand Island, N.Y.)medium containing trypsin inhibitor was added to the skin pieces.Complete MCDB 153 medium was made by supplementing basic MCDB 153(Gibco, Grand Island, N.Y.) medium, prepared as described by Boyce andHam [“Normal human epidermal keratinocytes,” In In Vitro Models forCancer Research (Weber and Sekely, eds.) CRC Press, Boca Raton, Fla.,pp. 245-274 (1985)], with 0.6 μM (0.218 μg/mL) hydrocortisone, 5 ng/mLepidermal growth factor, 5 μ/mL insulin, 6% bovine pituitary extract,and 0.15 mM CaCl₂.

The dermis was separated from the epidermis, and the epidermal basalcells were gently scraped off both segments of the skin. The cellsuspension was pooled into 50 mL conical centrifugation tubes, gentlycentrifuged at room temperature, and resuspended in 50 mL of completemedium plus 2% chelated serum.

The cells were counted using a hemacytometer, and 20×10⁶ cells wereplated into a T-75 Coming Plastic flasks and grown at 37 C with 5% CO₂gassing, using a humidified incubator. After 3 days, the used growthmedium was removed and complete MCDB 153 without serum was added. Thecells were fed every other day.

The cells were passaged during log phase of growth. Thereafter, thecells were trypsinized using 0.025% trypsin (type IX) plus 0.01% EDTA inthe HEPES buffer. The monolayers were washed with the buffer twice, then2-3 mL of freshly-made enzyme solution (or frozen aliquot) were added.After 1 min. at 37 C, the enzyme solution was gently aspirated off, andthe cells were placed in flasks at 37 C for 2-3 min. until the cellsheets came off the bottom with gentle tapping of the flask. The mediawas neutralized with 1-3 mL of MCDB 153 medium plus 0.03% trypsininhibitor (Sigma). The cells were counted, centrifuged, and plated 0.5to 1.0×10⁶ cells per T-75 flask. Cells were passaged 3 to 4 times.

CYTOLINE 1™ Bead Wash: Five grams of CYTOLINE 1™ macroporousmicrocarrier beads (Pharmacia Biotech) were autoclaved for 10 min. in 40mL Milli Q water (Millipore, Bedford, Mass.) in a 125 ml Erlenmeyerflask. Following the autoclaving procedures, the beads were cooled andthe water was aspirated. The beads were re-suspended in 40 mL Milli Qwater, and were then agitated at moderate speed on a Labline orbitalshaker for 10 min. The water was again aspirated, and a final washingwith 40 mL Milli Q water was performed.

The beads were transferred into a 50 mL conical culture tube, the waterwas aspirated, and 30 mL 0.1 N NaOH were added. The beads were incubatedat room temperature overnight. The NaOH solution was aspirated off thebeads, and the beads were resuspended in 50 mL Milli Q water. Thealiquot was transferred to a 125 Erlenmeyer flask and shaken at moderatespeed for ten minutes. The Milli Q water was aspirated off the beads,and the beads were resuspended in Milli Q water; thisaspiration/resuspension procedure was repeated a total of five times.The pH was neutral (i.e., less than 8), as measured with pH paper.

The beads were aspirated and resuspended in 40 mL PBS without Mg²⁺ andCa²⁺, and autoclaved 30 min. at 121 C.

Growth of Keratinocytes on CYTOLINE 1™ Beads: A slurry containing 10 mLof PBS solution and 5 g of beads (contained in a 50 mL sterile conicalcentrifuge tube) was autoclaved as described above. The PBS wasdecanted, and 50 mL of MCDB 153 complete medium was added to the beads.The cells were conditioned in the medium at 37 C with 5% CO₂ gas for 48hours.

The medium was decanted, and the beads were transferred into a separate50 mL sterile centrifuge tube. Ten-to-15 mL of medium were added, andthe suspension was centrifuged at 1000 rpm for 3 min. The medium wasagain decanted, and 30×10⁶ breast cells (from a living donor passage 1,never frozen) were added. After gently agitating the cells with thebeads for 5 minutes, the cells and beads were poured into a 250 mL glassroller bottle and 50 mL of medium was added; this was performed using afermentor-agitated growth system.

As a toxicity assay, 5 mL of cells and beads were removed from the glassroller bottle and grown in a T-25 flask to determine the growth of thecells on the plastic bottom of the flask in the presence of the beads.The roller bottle was incubated overnight at 37 C, after which 100 mLadditional medium was added to the roller bottle and the rotation of theroller bottle was initiated (rotation rate=one turn/15 sec.).

To feed the cells, an aliquot of medium was removed and replaced byfresh medium, adjusted to the correct pH with CO₂ gassing. The cellswere fed every 48 hours.

Experimental Design

An eight-day animal trial was conducted with two groups of ten animalseach. The wound dressings (see below) were changed every other daystarting on day 0. Wound area measurements and photographs were obtainedat days 0, 2, 4, 6, and 8.

All surgical procedures were performed under sterile conditions inside alaminar flow hood. Five-week old, female Nu/J mice (Jackson Labs) wereused. Nu/J mice contain a recessive mutation found on chromosome 11 andare athymic (T-cell deficient). The mice have a reduced lymphocyte countcomprised almost entirely of B-cells, a normal IgM response tothymus-independent antigens, a poor response to thymus antigens,increased macrophage and NK cell activity, and increased susceptibilityto infection. Nu/J mice do not reject allogeneic and xenogeneic skin andtumor grafts.

The mice were anesthetized with metofane (Mallinckrodt Veterinary) andprepped with ethanol. Using fine surgical scissors, a full thicknesssurgical wound approximately 80 mm² in area was created on the backs ofthe mice (the depth of the wound could be measure through the panniculuscarnosis, but mouse skin is so thin so it was not used as an indicatorhere). The wound dressings (see below) were secured to the cephalad endof the wound with a surgical staple. Thereafter, each mouse was returnedto its biohazard containment cage.

On days 2, 4, 6 and 8, the animals were returned to the laminar flowhood for removal of the staple and replacement of the bag. The animalswere lightly restrained while area and photographic measurements wereobtained (described below). The dressing was replaced and secured; alldressing changes were performed using sterile technique without generalanesthesia.

Wound Dressing

The wounds were dressed either with human cultured keratinocytes grownon beads (keratinocytes/beads) in a DELNET bag (P530 Natural; AET, Inc.)or a DELNET bag alone (P530 Natural; AET, Inc.); the DELNET bags wereapproximately square (about 23 mm×25 mm). The seams of the bags wereprepared with an Impulse heat sealing unit (American InternationalElectric Co.). Prior to application on the mice, the DELNET bags weregas sterilized with ethylene oxide and placed in a sterile package. ABANDAID (3M Healthcare) covered the DELNET bags and was secured withsurgical staples (Richard-Allen, Inc). The bag was stapled to theBANDAID, and the BANDAID was stapled to the mouse.

The bag and bead assembly was performed in a tissue culture hood. Insidea laminar flow hood, the keratinocytes/bead suspension was transferredto the DELNET bag with a glass pipet. Approximately 250 μL of thekeratinocyte/bead suspension was placed in the bag. After the beads wereloaded into the bag, the final seam was made with a surgical needleholder heated in a glass bead sterilizer. The DELNET bag containing thekeratinocytes/bead suspension is referred to as “beads/bag,” while theDELNET bag without the beads is referred to as “bag.” The bags andbeads/bags were placed in the complete MCDB 153 medium described aboveafter they were loaded and heat sealed.

Measurement of Wound Area

Total area of mouse wounds was performed as previously described[Schwarz et al., Wound Repair and Regeneration 3:204-212 (1995)].Briefly, the area of the wound was traced on transparency film (Apollo,Ronkonkoma, N.Y.) with a fine marker. The transparency film wasphotocopied onto plain paper and subsequently scanned into a PIC filewith a Lightning Scan Pro 256 hand scanner (Thunderware). Tissue areawas calculated with non-rectangular area analysis used by NIH image1.58, and the data was expressed as millimeters squared. Mean andstandard deviation were calculated using Statworks software (astatistically significant difference was p<0.05).

B. Experimental Results

Table 2 presents wound tissue area (mm²) at baseline (day 0) and at days2, 4, 6, and 8 for each mouse which received bags containingkeratinocyte-coated beads (beads/bags); the reduction in size of thewound as a percentage of the original wound size for each mouse is alsoset forth. Analogous data for the mice that received bags alone ispresented in Table 3.

Table 4 presents the cumulative data for i) the beads/bags mice and ii)the bags only mice. TABLE 2 Day 0 size (mm²) cells/bag mean 106.1 SD35.3 cells/bag tegaderm mean 103.1 SD 15.8 tet cells/bag mean 90.7 SD40.5 tet cells/bag tegaderm mean 92.7 SD 28.8 Day 3 Day 6 Day 9 Day 12Day 15 with with with with with % smaller bead/bag tegaderm bead/bagtegaderm bead/bag tegaderm bead/bag tegaderm bead/bag tegaderm TET OFFmean 13.2 0 34.2 2.2 74.4 52.4 84.6 81.2 99 98.6 Std Dev 17.5 0 14.5 4.310.9 21.1 10.5 13.8 2.2 3.1 significance p < 0.002 p < 0.07 TET ON mean7.2 70 25.4 84.6 65.2 97.8 92.2 100 100 100 Std Dev 10.2 7.2 15.9 11.920.5 2.6 6.8 0 0 0 significance p < 0.000 p < 0.000 p < 0.02 p < 0.05significance: Day 3 teg mice vs tet on teg mice p < 0.000 Day 6 teg micevs tet on teg mice p < 0.000 Day 9 teg mice vs tet on teg mice p < 0.004

TABLE 3 well ID OD value Result Sample Volume Factor (200 uL TV) EGF(pg/mL) Sample ID TET status Sept 26 Day 1 A 1 −0.004 0 25  6 off A 2−0.005 0 40  7 A 3 −0.005 0 30  8 A 4 −0.006 0 25  9 A 5 −0.004 0 25 10A 6 −0.003 0 5 16 ON A 7 −0.002 0 20 17 A 8 0.003 15.18 25 8 121.44 18 A9 0.001 11.24 50 4 44.96 19 A 10 0.005 19.03 50 4 76.12 20 Sept 29 Day 4A 11 0 9.23 50 4 36.92  6 off A 12 −0.003 0 20  7 B 1 −0.008 0 30  8 B 20.405 1081.45 20 10 10814.5 17 ON B 3 0.057 112.87 20 10 1128.7 18 B 40.19 380.92 20 10 3809.2 19 B 5 0.167 329.18 20 10 3291.8 20 Oct 18 Day1 B 6 −0.005 0 50  1 off B 7 −0.004 0 100  2 B 8 −0.005 0 100  3 B 9−0.005 0 10  4 B 10 −0.003 0 100  5 B 11 0.039 80.62 90 2.2 177.36 11 ONB 12 0.203 411.48 200 0 411.48 12 C 1 0.066 129.18 100 2 258.36 13 C 20.384 987.3 200 0 987.3 14 C 3 0.048 96.7 200 0 96.7 15 Oct 20 Day 3 C 4−0.005 0 200  2 off C 5 −0.002 0 200  4 C 6 −0.002 0 50 11 ON C 7 0.059116.488 200 0 116.48 12 C 8 0.082 158.59 200 0 158.59 13 C 9 0.088169.79 200 0 169.79 14 C 10 0.026 57.42 200 0 57.42 15

TABLE 4 Wound Measurements EGF Measurements Sept 25 Day 0 Sept 26 Day 1Wound size TET Off TET On EGF (pg/mL) Mouse TET status mean 103.1 92.7 07 off SD 15.8 28.8 0 8 0 9 0 10 0 16 ON 0 17 121.44 18 44.96 19 76.12 20Sept 28 Day 3 Sept 29 Day 4 % smaller TET Off TET On EGF (pg/mL) MouseTET status mean 0 70 36.92 6 off SD 0 7.2 0 7 0 8 10814.5 17 On 1128.718 3809.2 19 3291.8 20 Oct 1 Day 6 % smaller TET Off TET On mean 2.284.6 SD 4.3 11.9

As indicated by the data in Tables 2-4, the beads/bags showed astatistically significant difference in wound healing (i.e., a reductionin wound area) at day 2 compared to the bags alone (see Table 4,p<0.027). At day 4, the beads/bag (Table 2) treated mouse wounds had asignificant reduction in wound area compared to the mouse wounds in thebags alone (Table 3), as indicated by the significance level (p<0.008)in Table 4. At day 6, there was no significant difference in woundhealing between the two groups (see Table 3, p<0.16).

However, at day 8, there was again a statistically significant reductionin the wound area in the beads/bag group (Table 2) compared to the bagsalone group (Table 3) (see Table 4,p<0.05).

The experiments of this example show that cultured human keratinocytesgrown on a macroporous microcarriers (beads/bag) promote wound healing.The mouse model used is predicative that human keratinocytes grown on amacroporous microcarriers contained in bags will enhance wound healingin humans.

EXAMPLE 2

The experiments of this example demonstrate that human culturekeratinocytes grown on macroporous microcarriers and contained in aporous enclosure that is then covered with a wound dressing materialimprove healing in surgically created wounds in mice.

A. Experimental Methodology

The experiments of this example were performed as described in Example1, with the following exceptions. The group of mice that received thekeratinocyte-coated CYTOLINE 1™ macroporous microcarrier beads(Pharmacia Biotech) (i.e., the beads/bags group) comprised five animals,while the group that received only the bags (i.e., the bags only group)comprised four animals. (They are labelled 2 to 5 because Mouse 1expired during anesthesia.) In this example the bags from both thebeads/bags group and the bags only group were covered with apolyurethane film dressing (TEGADERM, 3M Health Care, St. Paul, Minn.)with a cellophane product.

More specifically, the wounds were dressed either with human culturedkeratinocytes grown on beads (keratinocytes/beads) in a DELNET bag (P530Natural; AET, Inc.) or a DELNET bag alone (P530 Natural; AET, Inc.).Thereafter, the bags were covered with a TEGADERM dressing which, inturn, was covered with a BANDAID (3M Healthcare). The bags were stapledto the mouse.

B. Experimental Results

Table 5 presents wound tissue area (mm²) at baseline (day 0) and at days2, 4, 6, and 8 for each mouse which received bags containingkeratinocyte-coated beads (beads/bags); the reduction in size of thewound as a percentage of the original wound size for each mouse is alsoset forth. Analogous data for the mice that received bags alone ispresented in Table 6.

Table 7 presents the cumulative data for i) the beads/bags mice and ii)the bags only mice. TABLE 5 mouse 1 mouse 2 mouse 3 mouse 4 mouse 5 daymm² % smaller mm² % smaller mm² % smaller mm² % smaller mm² % smaller 0109.78 120.56 124.67 114.67 134.44 cells 2 106.33 3.14 130 0.00 146.670.00 119.39 0.00 130.1 3.23 with Elof bags 4 123.33 0.00 112.78 6.45 1540.00 110.2 3.90 106.76 20.59 6 71.56 34.82 63.56 47.28 130.89 0.00 88.7822.58 130.48 2.95 8 65.44 40.39 48 60.19 48.89 60.78 36.73 67.97 70.4147.63 10  53.67 51.11 40 66.82 38 69.52 18.37 83.98 12.5 90.70 12  41.5662.14 23.33 80.65 8 93.58 16.58 85.54 8.93 93.36 mouse 6 mouse 7 mouse 8mouse 9 mouse 10 day mm² % smaller mm² % smaller mm² % smaller mm² %smaller mm² % smaller 0 112.37 121.28 149.82 109.63 123.17 cells 2119.86 0 83.23 31.37 147.44 1.59 127.83 0 127.27 0 with plastic wrap 483.23 25.93 73.84 39.12 91.32 39.05 138.48 0 86.77 29.55 6 89.89 20.0152.32 56.86 84.78 43.41 85.44 22.07 115.85 5.94 8 34.24 69.53 18.3184.90 32.34 78.41 47.94 56.27 31.07 74.77 10  17.12 84.76 15.7 87.0518.31 87.78 26.63 75.71 11.65 90.54 12  15.22 86.46 9.51 92.16 0 100 0100 0 100 mouse 11 mouse 12 mouse 13 mouse 14 mouse 15 day mm² % smallermm² % smaller mm² % smaller mm² % smaller mm² % smaller 0 124.14 107.02143.76 62.78 90.25 TET on cells 2 108.2 12.84 119.86 0.00 93.1 35.2486.21 0 113.2 0 with Elof bags 4 20.33 83.62 19.62 81.67 49.23 65.7665.64 0 27.82 69.17 6 11.89 90.42 0 100 0 100 21.4 65.91 0 100 8 0 100 0100 0 100 0 100 0 100 10  0 100 0 100 0 100 0 100 0 100 12  0 100 0 1000 100 0 100 0 100 mouse 16 mouse 17 mouse 18 mouse 19 mouse 20 day mm² %smaller mm² % smaller mm² % smaller mm² % smaller mm² % smaller 0 110148 117.11 139.33 152.11 TET on cells 2 138 0 124.67 15.76 105.78 9.67122.67 11.96 138.67 8.84 with plastic wrap 4 72 34.55 44.44 69.97 101.3313.47 80 42.58 84.33 44.56 6 0 100 13.33 90.99 11.56 90.13 19 88.3631.11 79.55 8 0 100 5.33 96.40 6.22 94.69 0 100 19.56 87.14 10  0 1003.33 97.75 5.44 95.35 0 100 39 74.36 12  0 100 0 100 0 100 0 100 1093.43

TABLE 6 % Day 2 Day 4 Day 6 Day 8 Day 10 Day 12 smaller TET Off TET OnTET Off TET On TET Off TET On TET Off TET On TET Off TET On TET Off TETOn Cells with Elof's bag mean 1.2 9.6 6.1 60 21.52 91.2 55.3 100 72.4100 83 100 Std Dev 1.7 15.3 8.5 34.4 20.3 14.7 11.1 0 15.5 0 12.9 0signifi- p = 0.004 p < 0.001 p = 0.014 p = 0.010 p = 0.008 cance Cellswith Plastic Wrap mean 6.5 9.2 26.7 41 29.6 89.4 72.7 77.6 85.1 93.495.7 98.6 Std Dev 13.8 5.8 16 20.3 20.2 7.4 10.7 38 5.6 10.8 6.1 2.9signifi- p < 0.001 cance Day 0 size (mm²) cells with Elof bag mean 120.8SD 9.4 cells with plastic wrap mean 123.2 SD 15.9 TET ON with Elof bagmean 105.5 SD 31.1 TET ON with plastic wrap mean 133.3 SD 18.7

TABLE 7 Wound Measurements EGF Measurements Oct 17 Day 0 Oct 18 Day 1Wound size TET Off TET On EGF (pg/mL) Mouse TET status mean 120.8 105.50 1 off SD 9.4 31.1 0 2 0 3 0 4 0 5 177.36 11 ON 411.48 12 258.36 13987.3 14 96.7 15 Oct 19 Day 2 Oct 20 Day 3 % smaller TET Off TET On EGF(pg/mL) Mouse TET status mean 1.2 9.6 0 2 off Std Dev 1.7 15.3 0 4 0 11ON 116.48 12 158.59 13 169.79 14 57.42 15 Oct 21 Day 4 % smaller TET OffTET On mean 6.1 60 Std Dev 8.5 34.4

As indicated by the data in Tables 5-7, the beads/bags demonstrated astatistically significant difference in wound healing (i.e., a reductionin wound area) at day 4 compared to the bags alone (see Table 7,p<0.026). The statistically significant difference in wound healingbetween the two groups was maintained on days 6 and 8 (p<0.010 andp<0.030, respectively).

Comparison of the data in Table 7 to that in Table 4 (Example 1)indicates that the wound dressings without TEGADERM begin to contractearlier than those with TEGADERM. More specifically, the wounds of thebeads/bags animals treated without TEGADERM were 12.7% smaller by day 2and 33.9% smaller by day 4, while the wounds of the beads/bags animalstreated with TEGADERM were 2.2% and 18.8% smaller on the same days.However, the size of the wounds of the beads/bags animals treated withTEGADERM became smaller than those treated without TEGADERM on days 6and 8. While an understanding of the mechanism for this effect is notrequired in order to practice the present invention, it is believed tobe due, in part, to the ability of the TEGADERM to keep the woundsmoist.

The experiments of this example indicate that the systems and methods ofthe present invention can be practiced in combination with conventionalwound healing means and procedures.

Based upon the preceding discussion and experimental materials, itshould be clear that the present invention provides effective andefficient systems and methods for wound healing, especially healing ofchronic wounds. The devices and methods may be used alone or incombination with other means traditionally employed in wound healing.

EXAMPLE 3

The experiments of this example demonstrate that a tetr-expressing cellline transfected with hEFG and grown on macroporous microcarriers andcontained in a porous enclosure, improves healing in surgically createdwounds in mice.

A. Experimental Methodology

Cells

Osteosarcoma line U20S were grown and maintained in Dulbecco's modifiedEagle's medium (DMEM) supplemented with 10% fetal bovine serum. ThetetR-expressing cell line, U2CEP4R-11, was cotransfected with pcDNA3,pcmvtetOEGF and EcoRI-linearized pcmvtetOEGF to establish cell linesthat expressed tetR and hEGF. Medium containing hygromycin B and G418was used to select cells resistant to hygromycin B. The hEGF-expressingcell lines were determined by analysis of hEGF expression in thepresence or absence of tetracycline. [See, Yao et al., Hum Gene Ther.1999 Feb. 10;10(3):419-27; and Yao et al., Hum Gene Ther. 1998 Sep.1;9(13):1939-50].

CYTOLINE I™ Bead Wash

Five grams of CYTOLINE I macroporous microcarrier beads (PharmaciaBiotech) were autoclaved for 10 minutes in 40 mL Milli Q water(Millipore, Bedford, Mass.) in a 125 mL Erlenmeyer flask. Following theautoclaving procedure, the beads were cooled and the water wasaspirated. The beads were re-suspended in 40 mL Milli Q water, and wereagitated at moderate speed on a Labline orbital shaker for 10 minutes.

The water was again aspirated, and a final washing with 40 mL Milli Qwater was performed. The beads were transferred into a 50 mL conicalculture tube, the water was aspirated, and 30 mL 0.1 N NaOH was added.Teh breads were incubated at room temperature overnight. The NaOH wasaspirated off the beads, and the beads were resuspended in 50 mL Milli Qwater. The aliquot was transferred to a 125 Erlenmeyer flask and shakenat moderate speed for ten minutes. The Milli Q water was aspirated offthe beads, and the beads were resuspended in Milli Q water; thisaspiration/resuspension procedure was repeated a total of five times.The pH was checked until neutral (i.e., less that 8), as measured withpH paper.

The beads were aspirated and resuspended in 40 mL PBS without Mg2+ andCa2+, and autoclaved 30 minutes at 121 C.

Growth of U20S cell line on CYTOLINE 1™ Beads

A slurry containing 10 mL of PBS solution and 5 grams of beads(contained in a 50 mL sterile conical centrifuge tube) was autoclaved asdescribed above. The PBS was decanted, and 50 mL of DMEM medium wasadded to the beads. The cells were conditioned in the medium at 37 Cwith 5% CO₂ gas for 48 hours.

The medium was decanted, and the beads were transferred into a separate50 ml sterile centrifuge tube. Ten-to-15 mL of medium was added, and thesuspension was centrifuged at 1000 rpm for 3 minutes. The medium wasagain decanted, and 30×10⁶ U20S transfected cells were added. Aftergently agitating for 5 minutes, the cells and beads were poured into a250 mL glass roller bottle and 50 mL of medium was added; this wasperformed using a fermentor-agitated growth system.

As a toxicity assay, 5 mL of cells and beads were removed from the glassroller bottle and grown in a T-25 flask to determine the growth of thecells on the plastic bottom of the flask in the presence of the beads.The roller bottle was incubated overnight at 37 C, after which 100 mLadditional medium was added to the roller bottle and the rotation of theroller bottle was initiated (rotation rate=one turn/15 seconds).

To feed the cells, an aliquot of medium was removed and replaced byfresh medium, adjusted to the correct pH with CO₂ gassing. The cellswere fed every 48 hours.

Experimental Design

A fifteen-day animal trial was conducted with two groups of ten animalseach. The wound dressings (see below) were changed every third daystarting at day 0. Wound area measurements and photographs were obtainedon days 0, 3, 6, 9, 12, and 15. Wound fluid collection occurred on days1 and 4.

All surgical procedures were performed under sterile conditions inside alamina flow hood. Five week old, male Nu/J mice (Jackson Labs) wereused. Nu/J mice contain a recessive mutation found on chromosome 11 andare athymic (T-cell deficient). The mice have a reduced lymphocyte countcomprised almost entirely of B-cells, a normal IgM response tothymus-independence antigens, a poor response thymus antigens, increasedmacrophage and NK cell activity, and increased susceptibility toinfection. NU/J mice do not reject allogeneic and xenogeneic skin andtumor grafts. Wounds in these mice heal poorly.

The mice were anesthetized with metofane (Mallinckrodt Veterinary) andprepped with ethanol. Using fine surgical scissors, a full thicknesssurgical wound approximately 98 mm² in area was created on the backs ofthe mice. The wound dressings (see below) were secured in the cephaladend of the wound with a surgical staple. Thereafter, each mouse wasreturned to its biohazard containment cage.

On day 1 and 4, the animals were returned to the laminar flow hood,lightly restrained and wound fluid was aspirated. On days 3,6,9,12, and15, the animals were returned to the laminar flow hood for removal ofthe staple and replacement of the bag. The animals were lightlyrestrained while area and photographic measurements were obtained(described below). The dressing was replaced and secured; all dressingchanges were performed using sterile technique without generalanesthesia.

Wound Dressing

The wounds were dressed either with U20S transfected cells grown onbeads or U20S transfected cells grown on beads in the presence of 1ug/mL tetracycline for 24 hours (tet on cells) before application. Bothgroups of cells and beads were enclosed in DELNET bags (P530 Natural;AET, Inc.) approximately 23 mm×25 mm. The seams of the bags wereprepared with an Impulse heat-sealing unit (American InternationalElectric Co.). Prior to filling and application on the mice, the DELNETbags were gas sterilized with ethylene oxide and placed in a sterilepackage. TEGADERM (3M Healthcare) covered the DELNET bags, a BANDAID (3MHealthcare) covered both and was secured with surgical staples(Richard-Allen, Inc.) in half of the mice. The TEGADERM adhered to theskin of the mouse, the bag and the BANDAID were stapled to the mouse.The remaining mice did not have TEGADERM covering the bag and wound.

The bag and bead assembly was performed in a tissue culture hood. Insidethe laminar flow hood, the U20S/bead suspensions were transferred to theDELNET bag with a sterile glass pipet. Approximately 250 μL of theU20S/bead suspension (with or without tetracycline exposure) was placedin the bag. After the beads were loaded into the bag, the final seam wasmade with an Impulse heat-sealer. The DELNET bag containing theU20S/bead suspension was referred to as “TET-Off cells,” while theDELNET bag with the suspension that was incubated 24 hours withtetracycline is referred to as “TET-On cells.” The TET-Off cells wereplace in DMEM medium while the TET-On cells were place in DMEM mediumwith 1 μL/mL tetracycline after they were loaded and heat-sealed.

Measurement of Wound Area

Total area of mouse wounds was performed as previously described[Schwarz et al., Wound Repair and Regeneration, 3:204-212 (1995)].Briefly, the area of the wound was traced on transparency film (Apollo,Ronkonkoma, N.Y.) with an ultra fine tip marker. The transparency filmwas photocopied onto plain paper and subsequently scanned into a bitmapfile using the HP ScanJet 4c (Hewlett Packard, Boise, Id.). Tissue areawas calculated with non-rectangular area analysis used by ImagePC (ScionCorp., Frederick, Md.) and the data was expressed as millimeterssquared. Mean and standard deviation were calculated using SigmaStatsoftware (SPSS Inc., Chicago, Ill.). A statistically significantdifference was considered as p<0.05.

Measurement of EGF Concentration

Wound fluid was collected 24 hours after the bead bag dressing wasapplied. Sterile saline (200 μL) was injected into the wound dressing tofacilitate in collecting any fluid that had collected overnight. Asyringe with a 24 gauge needle was used to collect the wound fluid. Thewound fluid was frozen in liquid nitrogen and stored until time ofanalysis.

The wells of a 96 well titer plate was coated with 125 ng of anti-EGFmonoclonal antibody. The wound fluid was added to the wells and adjustedto 200 μL (total volume) with growth medium. The reaction was carriedout at 4 C for 18 hours. The plate was then washed with PBS then 75 ngof anti-EGF polyclonal antibody was added and incubated for 3 hours. Theplate was washed again with PBS, 1:3000 dilution of HRP-Goat anti-rabbitantibody was added and incubated for 1.5 hours. The plate was washedwith PBS then the Bio-Rad HRP assay was run.

B. Experimental Results

Table 8 presents wound tissue area (mm²) at baseline (day 0) and at days3, 6, 9, 12, and 15 for each mouse that received bags containing U20Stransfected cells (TET Off cells) and U20S transfected cells exposed totetracycline (TET-On cells); the reduction in size of the wound as apercentage of the original wound size for each mouse is also set forth.Table 9 presents the cumulative data for i) the TET-Off mice and ii) theTET-On mice. TABLE 8 Cells/Beads only mouse 1 mouse 2 mouse 3 mouse 4mouse 5 Day mm² % smaller mm² % smaller mm² % smaller mm² % smaller mm²% smaller 0 72.33 68 128 113.33 113.33 3 84.44 0 63.56 7 105.78 17 65.4442 65.44 0 6 63.89 12 42.67 37 88 31 54 52 54 39 9 17.33 76 13 81 31.7875 18 84 18 56 12  24.89 66 6 91 17.78 86 10 91 10 89 15  3.89 95 0 1000 100 0 100 0 100 Cells/Beads with Tegaderm mouse 6 mouse 7 mouse 8mouse 9 mouse 10 ID (day) mm² % smaller mm² % smaller mm² % smaller mm²% smaller mm² % smaller 0 109.56 108.63 78 99.56 120 3 159 0 145 0156.44 0 177.22 0 133.78 0 6 122.67 0 116 0 77 1 136.89 0 107.56 10 938.89 65 39.11 64 45 42 80 20 35 71 12  36.67 67 32.11 70 8 90 20.44 790 100 15  7.78 93 0 100 0 100 0 100 0 100 TET “on” Cells/Beads mouse 11mouse 12 mouse 13 mouse 14 mouse 15 ID (day) mm² % smaller mm² % smallermm² % smaller mm² % smaller mm² % smaller 0 66.58 159.18 95.66 70.8961.11 3 114.41 0 172.58 0 75 22 86.33 0 52.78 14 6 81.38 0 94.9 40 65.4332 46.22 35 48.89 20 9 15.31 77 47.7 70 19.64 79 20.78 71 43.44 29 12  0100 23.85 85 3.83 96 10.67 85 3.33 95 15  0 100 0 100 0 100 0 100 0 100TET “on” Cells/Beads with Tegaderm mouse 16 mouse 17 mouse 18 mouse 19mouse 20 ID (day) mm² % smaller mm² % smaller mm² % smaller mm² %smaller mm² % smaller 0 68.88 89.29 134.44 64.44 106.78 3 26.79 61 30.6166 26.53 80 17.11 73 22.44 79 6 11.48 83 31.51 65 12.5 91 7.78 88 3.8996 0 2.68 96 died 6.25 95 0 100 0 100 12  0 100 0 100 0 100 0 100 15  0100 0 100 0 100 0 100

TABLE 9 Day 0 size (mm²) cells/bag mean 106.1 SD 35.3 cells/bag tegadermmean 103.1 SD 15.8 tet cells/bag mean 90.7 SD 40.5 tet cells/bagtegaderm mean 92.7 SD 28.8 Day 3 Day 6 Day 9 Day 12 Day 15 with withwith with with % smaller bead/bag tegaderm bead/bag tegaderm bead/bagtegaderm bead/bag tegaderm bead/bag tegaderm TET OFF mean 13.2 0 34.22.2 74.4 52.4 84.6 81.2 99 98.6 Std Dev 17.5 0 14.5 4.3 10.9 21.1 10.513.8 2.2 3.1 significance p < 0.002 p < 0.07 TET ON mean 7.2 70 25.484.6 65.2 97.8 92.2 100 100 100 Std Dev 10.2 7.2 15.9 11.9 20.5 2.6 6.80 0 0 significance p < 0.000 p < 0.000 p < 0.02 p < 0.05 significance:Day 3 teg mice vs test on teg mice p < 0.000 Day 6 teg mice vs tet onteg mice p < 0.000 Day 9 teg mice vs tet on teg mice p < 0.004

As indicated by the data in Tables 8-9, the TET-On cells with TEGADERMshowed a statistically significant difference in wound healing (i.e., areduction in wound area) at day 3 compared to TET-Off cells (see Table9, p<0.001). At day 6, the TET-On cells with TEGADERM treated mousewounds had a significant reduction in wound area compared to the TET-Offcells (Table 8), as indicated by the significance level (p<0.001) inTable 9. At day 9, there was no significance in wound healing betweenthe two groups (see Table 9, p<0.02). However, at day 12, there wasagain a statistically significant reduction in wound area in the TET-Ongroup compared to the TET-Off group (Table 8) (see Table 9, p<0.05).

The experiments of this example show the U20S transfected cells, exposedto tetracycline, grown on macroporous microcarriers (TET-On cells)promote wound healing. The mouse model is predicative that TET-Ontransfected cells grown on macroporous microcarriers contained in bagswill enhance wound healing in humans. Optimal conditions for thisexperiment to work was a consistently moist environment.

Table 10 shows the values of EGF that were in the wound fluid on day 1and day 4. These results were obtain 24 hours after application of thedressing. EGF was measurable in cells that had been treated withtetracycline (TET-On cells) while none was detectable in the non-treatedcells (TET-Off cells). Table 11 show the EGF results compared to thewound size over five days. TABLE 10 well ID OD value Result SampleVolume Factor (200 uL TV) EGF (pg/mL) Sample ID TET status Sept 26 Day 1A 1 −0.004 0 25  6 off A 2 −0.005 0 40  7 A 3 −0.005 0 30  8 A 4 −0.0060 25  9 A 5 −0.004 0 25 10 A 6 −0.003 0 5 16 ON A 7 −0.002 0 20 17 A 80.003 15.18 25 8 121.44 18 A 9 0.001 11.24 50 4 44.96 19 A 10 0.00519.03 50 4 76.12 20 A 11 0 9.23 50 4 36.92  6 off A 12 −0.003 0 20  7 B1 −0.008 0 30  8 B 2 0.405 1081.45 20 10 10814.5 17 ON B 3 0.057 112.8720 10 1128.7 18 B 4 0.19 380.92 20 10 3809.2 19 B 5 0.167 329.18 20 103291.8 20 Oct 18 Day 1 B 6 −0.005 0 50  1 off B 7 −0.004 0 100  2 B 8−0.005 0 100  3 B 9 −0.005 0 10  4 B 10 −0.003 0 100  5 B 11 0.039 80.6290 2.2 177.36 11 ON B 12 0.203 411.48 200 0 411.48 12 C 1 0.066 129.18100 2 258.36 13 C 2 0.384 987.3 200 0 987.3 14 C 3 0.048 96.7 200 0 96.715 Oct 20 Day 3 C 4 −0.005 0 200  2 off C 5 −0.002 0 200  4 C 6 −0.002 050 11 ON C 7 0.059 116.488 200 0 116.48 12 C 8 0.082 158.59 200 0 158.5913 C 9 0.088 169.79 200 0 169.79 14 C 10 0.026 57.42 200 0 57.42 15

TABLE 11 Wound Measurements EGF Measurements Sept 25 Day 0 Sept 26 Day 1Wound size TET Off TET On EGF (pg/mL) Mouse TET status mean 103.1 92.7 07 off SD 15.8 28.8 0 8 0 9 0 10 0 16 ON 0 17 121.44 18 44.96 19 76.12 20Sept 28 Day 3 Sept 29 Day 4 % smaller TET Off TET On EGF (pg/mL) MouseTET status mean 0 70 36.92 6 off SD 0 7.2 0 7 0 8 10814.5 17 On 1128.718 3809.2 19 3291.8 20 Oct 1 Day 6 % smaller TET Off TET On mean 2.284.6 SD 4.3 11.9

Although expression of EGF was under regulatory control by tet, it willbe appreciated that any regulatory system (or nonregulatory system) maybe employed. In addition, physical removal of the enclosure may also beused to “regulate” the amount of cell factors or proteins of interestdelivered to a target site.

EXAMPLE 4

The experiments of this example demonstrated that tet-R expressing cellline transfected with hEGF and grown on macroporous microcarrier andcontained in a porous enclosure improves healing in surgically createdwound in mice.

A. Experimental Methodology

The experiments of this example were performed as described in Example 3with the following exceptions. This was a 12-day animal trial with twogroups of ten animals each. The wound dressing was changed every otherday starting on day 0. Wound measurements were obtained days 8, 10, and12. Wound fluid collection occurred on days 1 and 3. Ten of the mice hadtheir bead/cell bag covered wound enclosed in an occlusive collectionsystem as described in U.S. Pat. No. 5,152,757 (hereby incorporated byreference). The remaining 10 mice bead/cell bag covered wounds wereenclosed with plastic film (Dow Chemical Co.).

More specifically, the wounds were dressed with either an occlusivecollection system or plastic film to provide better wound healingconditions as shown in Example 3. Covering the wounds in this manneralso facilitated in the collection of wound fluid for EGFdeterminations. The wounds were covered with the bead/bag then thecollection system was adhered to the back of the mice and stapled to theskin. A BAND AID adhesive bandage was used to adhere the plastic film tothe back of the mice and stapled as in Example 3.

B. Experimental Results

Table 12 presents wound tissue area (mm²) at baseline (day 0) and atdays 2, 4, 6, 8, 10, and 12 for each mouse that received bags containingU20S transfected cells (TET-Off cells) and U20S transfected cellsexposed to tetracycline (TET-On cells); the reduction in size of thewound as a percentage of the original wound size for each mouse is alsoset forth. Table 13 presents the cumulative data for i) the TET-Off miceand ii) the TET On mice. TABLE 12 mouse 1 mouse 2 mouse 3 mouse 4 mouse5 day mm² % smaller mm² % smaller mm² % smaller mm² % smaller mm² %smaller 0 109.78 120.56 124.67 114.67 134.44 cells 2 106.33 3.14 1300.00 146.67 0.00 119.39 0.00 130.1 3.23 with Elof bags 4 123.33 0.00112.78 6.45 154 0.00 110.2 3.90 106.76 20.59 6 71.56 34.82 63.56 47.28130.89 0.00 86.78 22.58 130.48 2.95 8 65.44 40.39 48 60.19 48.89 60.7836.73 67.97 70.41 47.63 10  53.67 51.11 40 66.82 38 69.52 18.37 83.9812.5 90.70 12  41.56 62.14 23.33 80.65 8 93.58 16.58 85.54 8.93 93.36mouse 6 mouse 7 mouse 8 mouse 9 mouse 10 day mm² % smaller mm² % smallermm² % smaller mm² % smaller mm² % smaller 0 112.37 121.28 149.82 109.63123.17 cells 2 119.86 0 83.23 31.37 147.44 1.59 127.83 0 127.27 0 withplastic wrap 4 83.23 25.93 73.84 39.12 91.32 39.05 138.48 0 86.77 29.556 89.89 20.01 52.32 56.86 84.78 43.41 85.44 22.07 115.85 5.94 8 34.2469.53 18.31 84.90 32.34 78.41 47.94 56.27 31.07 74.77 10  17.12 84.7615.7 87.05 18.31 87.78 26.63 75.71 11.65 90.54 12  15.22 86.46 9.5192.16 0 100 0 100 0 100 mouse 11 mouse 12 mouse 13 mouse 14 mouse 15 daymm² % smaller mm² % smaller mm² % smaller mm² % smaller mm² % smaller 0124.14 107.02 143.76 62.78 90.25 TET on cells 2 108.2 12.84 119.86 0.0093.1 35.24 86.21 0 113.2 0 with Elof bags 4 20.33 83.62 19.62 81.6749.23 65.76 65.64 0 27.82 69.17 6 11.89 90.42 0 100 0 100 21.4 65.91 0100 8 0 100 0 100 0 100 0 100 0 100 10  0 100 0 100 0 100 0 100 0 10012  0 100 0 100 0 100 0 100 0 100 mouse 16 mouse 17 mouse 18 mouse 19mouse 20 day mm² % smaller mm² % smaller mm² % smaller mm² % smaller mm²% smaller 0 110 148 117.11 139.33 152.11 TET on cells 2 138 0 124.6715.76 105.78 9.67 122.67 11.96 138.67 8.84 with plastic wrap 4 72 34.5544.44 69.97 101.33 13.47 80 42.58 84.33 44.56 6 0 100 13.33 90.99 11.5690.13 19 86.36 31.11 79.55 8 0 100 5.33 96.40 6.22 94.69 0 100 19.5687.14 10  0 100 3.33 97.75 5.44 95.35 0 100 39 74.36 12  0 100 0 100 0100 0 100 10 93.43

TABLE 13 % Day 2 Day 4 Day 6 Day 8 Day 10 Day 12 smaller TET Off TET OnTET Off TET On TET Off TET On TET Off TET On TET Off TET On TET Off TETOn Cells with Elof's bag mean 1.2 9.6 6.1 60 21.52 91.2 55.3 100 72.4100 83 100 Std Dev 1.7 15.3 8.5 34.4 20.3 14.7 11.1 0 15.5 0 12.9 0signifi- p = 0.004 p < 0.001 p = 0.014 p = 0.010 p = 0.008 cance Cellswith Plastic Wrap mean 6.5 9.2 26.7 41 29.6 89.4 72.7 77.6 85.1 93.495.7 98.6 Std Dev 13.8 5.8 16 20.3 20.2 7.4 10.7 38 5.6 10.8 6.1 2.9signifi- p < 0.001 cance Day 0 size (mm²) cells with Elof bag mean 120.8SD 9.4 cells with plastic wrap mean 123.2 SD 15.9 TET ON with Elof bagmean 105.5 SD 31.1 TET ON with plastic wrap mean 133.3 SD 18.7

As indicated by the data in Tables 12 and 13, the TET-On cells with theocclusive collection system showed a statistically significantdifference in wound healing (i.e., a reduction in wound area) at day 4compared to the TET-Off cells (see Table 13, p=0.004). At days 6, 8, 10,and 12, the data still showed significance difference in wound healingcompared to the TET-Off cells (see Table 13, p<0.014).

The experiments of this example show the U20S transfected cells, exposedto tetracycline, grown on macroporous microcarriers (TET-On cells)promote wound healing. The mouse model is predicative that TET-Ontransfected cells grown on macroporous microcarriers contained in bagswill enhance wound healing in humans.

Table 10 shows the values of EGF that were in the wound fluid on day 1and day 3. These results were obtain 24 hours after application of thedressings. EGF was measurable in cells that had been treated withtetracycline (TET-On cells) while none was detectable in the non-treatedcells (TET-Off cells). Table 14 show the EGF results compared to thewound size over four days. TABLE 14 Wound Measurements EGF MeasurementsOct 17 Day 0 Oct 18 Day 1 Wound size TET Off TET On EGF (pg/mL) MouseTET status mean 120.8 105.5 0 1 off SD 9.4 31.1 0 2 0 3 0 4 0 5 177.3611 ON 411.48 12 258.36 13 987.3 14 96.7 15 Oct 19 Day 2 Oct 20 Day 3 %smaller TET Off TET On EGF (pg/mL) Mouse TET status mean 1.2 9.6 0 2 offStd Dev 1.7 15.3 0 4 0 11 ON 116.48 12 158.59 13 169.79 14 57.42 15 Oct21 Day 4 % smaller TET Off TET On mean 6.1 60 Std Dev 8.5 34.4

Based upon the preceding discussion and experimental materials, itshould be clear that the present invention provides effective andefficient systems and methods for wound healing, especially healing ofchronic wounds. The devices and methods may be used alone or incombination with other means traditionally employed in wound healing.

EXAMPLE 5 Preparing Enclosures

Preparation of Cells: A method of isolating keratinocytes, seeding solidsupport means with keratinocytes, and introducing cell-seeded supportmeans into an enclosure is described in U.S. Pat. No. 5,972,332 (herebyincorporated by reference). Similar methodology is described for atransformed cell line expressing a transgene in U.S. patent applicationSer. No. 09/323,188 filed May 27, 1999 and in U.S. Ser. No. 09/338,413,filed Feb. 11, 2000. Each referenced patent and application isincorporated herein in its entirety by reference. Virtually any othercell type that is mitotically competent in a cell culture medium couldbe selected by the skilled practitioner depending upon the specificpurpose for which the subject article is to be used. Primary isolatesmay be seeded onto solid support means immediately, or passaged one ormore times in cell culture before seeding. In the case of keratinocytes,the cell culture medium contains microgram per ml amounts of insulin,calcium (at concentrations lower than normal serum concentrations),microgram per ml amounts of a glucocorticoid, nanogram/ml amounts ofepidermal growth factor, and nanogram/ml amounts of a saline extract ofbovine pituitary.

Preparation of Solid Support Means: A solid support means with thefollowing features is selected:

-   -   (i) Preferably, the solid support means is substantially        incapable of escaping the enclosure. In this example,        macroporous beads made of polyethylene and silica, sized to be        large enough to stay inside an enclosure made of DELNET (P530        Natural, AET, Inc.) but otherwise small enough to maximize the        surface area that a plurality of the beads provides for cell        attachment and cell growth, were selected.    -   (ii) The solid support means preferably has a higher avidity for        cells than for the selected enclosure material or the culture        medium. In this case, the selected beads were treated with a        solution of sodium hydroxide to effect this result, presumably        by rendering the beads more negatively charged than the        enclosure material or the culture medium.    -   (iii) A solid support means that is non-toxic to the cells        (within the limits of the viability test described herein) is        selected.

In the instant example, the selected solid support means, macroporousmicrocarrier beads made of polyethylene and silica, were autoclaved at121° C. for 10 minutes in double distilled or microfiltered water.Following the autoclaving procedure, the beads were allowed to settle bygravity and were cooled. The supernatant water was then aspirated awayfrom the beads. The beads were re-suspended in double distilled ormicrofiltered water and agitated by hand-swirling for a few seconds. Thebeads were again allowed to settle, the water aspirated and a finalwashing performed as above.

The beads were next treated with a solution of 0.1N NaOH, a preferredconcentration, but not critical. Treatment continued at room temperatureovernight. Thereafter the washing procedure set out above was repeatedfive times. The pH of the final suspension was measured with aconventional device at less than about 8. The beads were thentransferred to sterile culture medium, at which point they are ready forseeding.

Preparation of the Enclosure: Variations in the procedure result inseveral embodiments of the final article.

-   -   (i) A sheet of DELNET, approximately 3×6 inches was folded once        into a square shape and heat-sealed on two sides using a        heat-sealing unit (IMPULSE manufactured by American        International Electric Co.) to create a bag-like structure.        Next, beads prepared as described above were introduced into the        bag through the unsealed side. Approximately 1 ml of        gravity-packed beads was introduced into the bag. The open side        of the bag was then heat-sealed as above. The article was then        immediately placed in culture medium, heat-sterilized at 121° C.        for 30 minutes and stored in the culture medium for use in        subsequent steps.    -   (ii) The bag prepared as described above, after equilibrating in        culture medium at 37° C. for 4 days or more was inoculated with        a primary culture of more than about one million keratinocytes        per ml of gravity-packed beads and less than about two million        keratinocytes per ml of gravity-packed beads. The keratinocytes        were suspended in culture medium in a 3 cc syringe and injected        through the DELNET material using an 18 ga. needle. The injected        bag was then incubated, using conventional tissue culture        apparatus, in approximately 1 ml of culture medium for 4 days at        37° C. under 95% O₂, 5% CO₂. The article was then ready for use.        Alternatively, the bag and its contents may be frozen and used        at a later time, after thawing.    -   (iii) A sheet of DELNET is fashioned into an open bag-like        structure and sterilized. Cells pre-seeded onto sterile,        equilibrated solid-support means are introduced into the bag and        the bag is then sealed by means that are non-toxic to the cells.        The sealed bag is then incubated as described above or for a        time sufficient to permit growth of cells to a pre-determined        number and then put to use or frozen for use at a later time.    -   (iv) A sheet of DELNET is fashioned into an open bag-like        structure and sterilized. Cells in suspension and, separately,        sterile, equilibrated solid-support means are introduced into        the bag and the bag is then sealed by means that are non-toxic        to cells. The sealed bag is then incubated as described above        and put to use or frozen for use at a later time.    -   (v) Cells in suspension and, separately, sterilized        solid-support means are introduced into a sterilized, entirely        sealed enclosure. The enclosure is then incubated as described        above and put to use or frozen for use at a later time. The        frozen article is made useable by thawing and, using        conventional tissue culture apparatus, incubating the article in        culture medium for a sufficient time to permit seeding and        growth of cells to a pre-determined number.    -   (vi) Cells in suspension are introduced into either an open bag        or an entirely sealed bag and frozen. Separately, an        equilibrated, sterile solid-support means is introduced into the        same bag, sealed by an appropriate means if necessary, and        frozen. At a later time, the bag is thawed and, using        conventional tissue culture apparatus, incubated in culture        medium for a sufficient time to permit seeding and growth of        cells to a pre-determined number. The article is then ready for        use.    -   (vii) An enclosure prepared as in (i) above is co-incubated with        cells. However, the cells are not injected into the enclosure,        but migrate into the enclosure. When the extent of cell        immigration is sufficient to effect seeding of the solid support        means, incubation of the enclosure and its contents continues,        with or without replacement of the medium with cell-free medium,        to permit growth of cells on the solid-support means to a        pre-determined number. The Article is then put to use or frozen        for use at a later time. The frozen article is made useable by        thawing and, using conventional tissue culture apparatus,        incubating the article in culture medium for a sufficient time        to permit seeding and growth of cells to a pre-determined        number.

Growing the Cells: Whether or not grown within or without the enclosure,cells were added to beads at a density of less than about two millioncells per 1 ml of gravity-packed beads. Cells were grown in an incubatorwith slow agitation in a roller bottle. Cells attached to the beadswithin about 6 hours. The incubation medium was changed every other day.The temperature ranged between 36 and 38° C. and the medium was gassedwith 5%CO₂-95%O₂.

Procedure for Assessing Viability of Cells in Enclosure:

Reagents:

-   1 μM calcein AM*+2 μM EthD-1* in D-PBS-   1 μM calcein AM in D-PBS-   2 μM EthD-1 in D-PBS-   Dulbecco's Buffered Phosphate Saline (D-PBS)    *Molecular Probes, LIVE/DEAD Viability/Cytotoxicity Kit (L-3224)    Solution Preparation for Experimental and Control Cell Samples:

Use within 24 hours of making

Solution 1. Combination Solution (Live/Dead Cells)

Add 20 μl EthD-1 to 10 ml D-PBS

Vortex to mix

Add 5 μl calcein to EthD-1 solution

Vortex to mix

Solution 2. Calcein Solution (Live Cells)

Add 5 μl calcein to 10 ml D-PBS

Vortex to mix

Solution 3. EthD-1 Solution (Dead Cells)

Add 20 μl EthD-1 to 10 ml PBS

Vortex to Mix

Experimental Sample Preparation:

-   Open a bag of cells/beads and place into a 35 mm Petri dish.-   Aspirate the media.-   Rinse cells/beads immediately with 3 ml of D-PBS.-   Place aliquots of cells/beads into 4 Petri dishes for different    treatments.-   Aspirate the D-PBS.-   Add enough of the combination solution (solution 1) to cover the    cells/beads.-   Incubate Petri dish at 37 degrees Celsius for 20 minutes.-   View Petri dish under fluorescence microscope to confirm the cells    have stained appropriately. (live cells: ex/em ˜485/˜530; dead    cells: ex/em ˜530/˜645)-   Randomly pick cells/beads from Petri dish and place into a 96 well    plate.    Control Samples Preparation:    Plain Bead Controls:-   Take plain prepared beads and place approximately 500 μl into 2    Petri dishes.-   Aspirate soaking solution.-   Rinse plain prepared beads with 3 ml of D-PBS.-   Aspirate the D-PBS.-   Add enough of Solution 2 to one Petri dish and Solution 3 to the    remaining Petri dish to cover the beads.-   Indubate Petri dishes at 37 degrees Celsius for 20 minutes.-   Randomly pick beads and place into a 96 well plate.-   Also take plain prepared beads (no solution treatments), rinsed in    D-PBS and place into a 96 well plate.    Cells/Bead Controls:-   Take one of the cell/bead aliquot dishes and aspirate the D-PBS.-   Add enough of the Calcein solution (solution 2) to cover the    cells/beads.-   Take another of the cell/bead aliquot dish and aspirate the D-PBS.-   Add enough of the EthD-I solution (solution 3) to cover the    cells/beads.-   Take a third cell/bead aliquot dish and aspirate the D-PBS.-   Add enough D-PBS to cover the cells/beads.-   Incubate all Petri dishes at 37 degrees Celsius for 20 minutes.-   Randomly pick beads and place into a 96 well plate.    96 Well Plate Set Up:-   Pipet 100 μl D-PBS into all wells, 2-3 beads per well-   Add plain bead controls, cells/beads controls and experimental    samples to multiple wells for analysis.    Microplate Reader Set Up:-   Follow the instrument's procedure manual for setting up the reader    for the appropriate filters and running the assay.-   Calcein is excited using a fluorescein filter, 485±10 nm and an    emission filter of 530±12.5 nm.-   Ethidium homodimer-1 (EthD-1) is excited with a rhodomine filter,    530±12.5 nm and an emission filter of 645±20 nm.    Fluorescence Measurements:-   Run the assay first utilizing the Calcein set of filters then repeat    the assay with the Ethidium filter set.-   Background fluorescence (plain bead control) readings are subtracted    from experimental sample wells.-   Viability=ratio of live cells values (Calcein assay) to dead cells    values (Ethidium assay). Note: The minimum detectable number of    cells per well is usually between 200 and 500. The maximum usable    number of cells per well is on the order of 106 (Ref., LIVE/DEAD    Viability Kit, Molecular Probes Inc., Information sheet).

EXAMPLE 6 Enclosures for Promoting Tumor Regression

This example describes enclosures and methods used to promote tumorregression. In particular, this example describes the use of enclosurescontaining cells transfected with human interleukin-1 (hIL-1) to reducethe size of tumors.

Mouse macrophage cells, RAW 264, were transfected with IL-1. The primersequence for IL-1 was obtained from GeneBank. The primers employed were5′ ATGGCACCTGTACGATCACT 3′ (SEQ ID NO:1) and 5′ TTCAGCACAGGACTCTCTGG 3′(SEQ ID NO:2). cDNA fragments were generated by RT-PCR from humanleukocytes. These fragments were cloned into the TA cloning vector(Invitrogen, Carlsbad, Calif.) and then subcloned into pcDNA4/TOexpression Vector for the T-Rex system (Invitrogen, Carlsbad, Calif.).Orientation of the insert was confirmed by restriction enzyme digestion.DNA was prepared by using the Novagen UltraMobius Plasmid Isolation kit(Novagen, Madison, Wis.) to reduce endotoxin comtamination. The finalDNA concentration for hIL-1 was 980 μg/ml. The LIPOFECTAMIN PLUS™ kit(Life Technologies, Rockwell, Md.) was use to perform the transfection.The plasmid was diluted in medium to 10 μg/ml then mixed with PLUSreagent and incubated. LIPOFECTAMINE was added to this mixture andincubated before being added to the RAW cells in culture.

The mouse macrophage cells RAW 264 were seeded onto CYTOLINE 1macroporous microcarrier beads (Pharmacia Biotech, Uppsala, Sweden) at aconcentration of 1×10⁶ cells per 1 ml of microcarrier beads and allowedto attach for 2 days. The LIPOFECTAMIN hIL-1 mixture was combined withthe RAW cells/beads and incubated. After 3 hours the transfected cellpopulated microcarrier beads were pipeted into fabric bag enclosure (0.5ml beads per 23×25 cm bag) composed of DELNET material, and maintainedin medium until application. The enclosure remained on the tumor onlytwo days because the transfection was transient and was lost after 48hour.

Twelve C57BLK/J mice had BL6 melanoma injected intramuscularly betweenthe scapula with a tumor developing by 10 days. At that time the tumorwas incompletely excised and the enclosure was placed over the remainingtumor and the wound closed over it using surgical staples. After 2 daysthe dressing was removed and the tumor was evaluated for size reductionor tumor recurrence over 21 days. A second group of mice (control) hadtheir tumors incompletely excised, an enclosure with parentalnon-transfected RAW cells placed over the tumor and the wound closed. At24 and 48 hours both groups of mice had blood and wound fluid collectedfor IL-1 determination by ELISA.

Eight of the nine mice treated with hIL-1 transfected cells had noremaining tumor or had regression of the tumor. The three control micetreated with the non-transfected RAW 264 cells showed continued tumorgrowth. These results are present in FIG. 2. The top images in FIG. 2are of a mouse that was treated with IL-1 transfected cell-containingenclosures, while the bottom images are of a control mouse. Images inthe left column are from day 2, when the enclosure was removed from themouse. The right column shows the tumor size at day 10. Note therecurrence of the melanoma in the control mouse at day 10. Also, ninemice lungs were evaluated for metastasis with none observed.

ELISA analysis of IL-1 from serum sample detected none at either 24 or48 hours. However, wound fluid from four randomly selected IL-1 treatedmice averaged 991 pg/ml±508 at 24 hours and 74 pg/ml±37 at 48 hours. Twocontrol mice chosen had no detectable IL-1. Medium from the unused IL-1cells/beads flasks contained 25,431 pg/ml of IL-1 while the controlcells/beads medium had no detectable IL-1. These results are presentedin Table 15. TABLE 15 ELISA Results of Individual Mice Mouse 24 hrs(pg/ml) 48 hrs (pg/ml) IL-1 Treated 1 244 71 2 740 176 3 495 49 4 2481155 Control Treated 5 <1.22 <1.22 6 <1.22 <1.22 Stock Cell ControlMedium IL-1 cell/bead flask 25,431 Medium non-transfected cell/beadflask <1.22

EXAMPLE 7 Tumor Susceptibility Data

This example describes a tumor susceptibility assay. In particular, wasperformed to determine if melanoma growth onto the beads was preventedin murine macrophages that were transfected with the gene encoding forIL-1

In this series of experiments, BL16 tumors were grown in the soft tissueof the back of C57/BLK/J mice. The tumors were incompletely excised andbead bags were placed on the wound. The bead bags contained the raw 264macrophages grown on beads with or without cells transfected with thegene that encode for IL-1. The beads were removed from the bag after 48hrs and placed in a petri dish. The difference in the number of beads orbead clumps containing black pigment were counted without magnification.The number beads/bead clumps with black pigment were expressed as apercentage of the total of the number counted.

The data demonstrates that beads containing the raw 264 macrophagestransfected with the gene encoding for IL-1 had only 8% (2/50)beads/bead clumps containing black melanoma pigment. Whereas, 68%(24/34) bead/bead clumps contained black pigment if the raw 264macrophages were not transfected with the gene that encoded for IL-1.This data indicates, since macrophages transfected with the gene thanencodes for the production IL-1 prevents melanoma growth on thebead/bead clumps in vitro, that the tumor that was the source of themelanoma cells would be susceptible to treatment with enclosurescontaining these cells.

All publications and patents mentioned in the above specification areherein incorporated by reference. Various modifications and variationsof the described method and system of the invention will be apparent tothose skilled in the art without departing from the scope and spirit ofthe invention. Although the invention has been described in connectionwith specific preferred embodiments, it should be understood that theinvention as claimed should not be unduly limited to such specificembodiments. Indeed, various modifications of the described modes forcarrying out the invention which are obvious to those skilled inchemistry, and molecular biology or related fields are intended to bewithin the scope of the following claims.

1. A method for producing a cell-containing enclosure, comprising; a)providing, i) viable cells on solid support material, ii) a nucleic acidsequence encoding a therapeutic protein, wherein said therapeuticprotein promotes tumor regression, and iii) an enclosure configured forhousing said solid support material, wherein said enclosure comprisesmesh material, b) transfecting said viable cells on said solid supportmaterial with said nucleic acid sequence, and c) placing said solidsupport material into said enclosure to produce a cell-containingenclosure capable of promoting tumor regression.
 2. The method of claim1, wherein said therapeutic protein is a cytokine.
 3. The method claim1, wherein said therapeutic protein is interleukin-1.
 4. The method ofclaim 1, wherein said nucleic acid sequence comprises at least a portionof an interleukin-1 gene sequence.
 5. The method of claim 1, whereinsaid solid support material comprises macroporous beads.
 6. The methodof claim 1, wherein said mesh material comprises pores.
 7. The method ofclaim 1, wherein said mesh material comprises pores ranging in size fromabout 1 micron to about 500 microns.
 8. The method of claim 1, furthercomprising the step of sealing said enclosure.
 9. The method of claim 1,further comprising the step of freezing said cell-containing enclosure.10. A cell-containing enclosure configured for promoting tumorregression produced by the method of claim
 1. 11. A method for promotingtumor regression, comprising; a) providing; i) viable cells on solidsupport material, wherein said viable cells secrete at least onetherapeutic protein, ii) an enclosure housing said solid supportmaterial, wherein said enclosure comprises mesh material, and iii) asubject with a tumor, b) positioning said enclosure on said tumor ofsaid subject such that regression of said tumor is promoted.
 12. Themethod of claim 11, wherein said therapeutic protein is a recombinantprotein.
 13. The method of claim 12, wherein said recombinant protein isa cytokine.
 14. The method of claim 12, wherein said recombinant proteincomprises interleukin-1.
 15. The method of claim 11, wherein said viablecells comprise an expression vector, wherein said expression vectorcomprises a nucleic acid sequence encoding said therapeutic protein. 16.The method of claim 11, wherein said nucleic acid sequence comprises atleast a portion of an interleukin-1 gene sequence.
 17. The method ofclaim 11, wherein said solid support comprises beads.
 18. The method ofclaim 11, wherein said mesh material comprises pores.
 19. The method ofclaim 11, wherein said mesh material comprises pores ranging in sizefrom about 1 micron to about 500 microns.
 20. The method of claim 11,wherein said enclosure further comprises a removal component.
 21. Themethod of claim 11, further comprising step c) removing said enclosurefrom said tumor after regression of said tumor is promoted.
 22. Themethod of claim 11, wherein said tumor is a cancerous tumor.
 23. Themethod of claim 22, wherein said cancerous tumor is a skin cancer tumor.